Cursus Philosophicus Thomisticus, Secunda Pars Artis Logicae

Almost the whole DIFFICULTY of this article depends on understanding the terms stated in its title.

First, we are speaking of the art of Logic, that is, artificial Logic, not natural Logic. Natural Logic is nothing other than natural light itself using reasoning. This natural light is not the intellect's bare potency, but the intellect together with the habit of principles that are naturally known. Yet those principles are not the science or art itself; the habit of principles and the habit of an art or science are very distinct habits. When we inquire into the necessity of Logic, there is no difficulty about Logic's principles or the habit of its principles, which some abusively call preceptive or actual Logic, since this is not Logic but its principle.

Second, by “science” one may mean science only in substance, in an imperfect state, as science is generated in substance in the first demonstration—that is, by convincingly and certainly and evidently persuading the intellect. Or one may mean science in its perfect state, which simply denominates someone a knower: the science by which the intellect is not only convinced but can also reason on its own about what pertains to full knowledge of that science's object, and defend itself against contrary errors or attacks. In the present inquiry into Logic's necessity for science, “science” may be taken in either sense.

Third, the title asks whether Logic is necessary without qualification. Here “necessary without qualification” does not mean “absolutely necessary,” which is taken from the side of an intrinsic cause, whether matter or form, as it is necessary for a human being to be rational and mortal. Rather, it means necessary with reference to something else, that is, to the attainment of some end. Necessity for an end is said in two ways: something is necessary without qualification or necessary in a certain respect. It is necessary without qualification when required for the very being of a thing, either to acquire or to preserve it, as food and breathing are required for living. It is necessary in a certain respect when required for well-being, that is, for some greater convenience or adornment, not for being itself as such. On these divisions of absolute and relative necessity, and of necessity without qualification and in a certain respect, see St. Thomas, Metaphysics V, lect. 6¹.

Since no one doubts, then, that Logic is at least useful and necessary in a certain respect—that is, for the sciences' better and more convenient condition—the whole difficulty reduces to whether Logic is necessary without qualification.

RESOLUTION.

LET THERE BE ONE CONCLUSION: Artificial Logic is necessary without qualification for the speculative sciences with respect to science's perfect state and its preservation and, as it were, nourishment; it is not necessary with respect to science's imperfect being and its first generation, as it were.

Thus it can be called necessary without qualification, with no further qualification, but not necessary without qualification in every way. Breathing and food, for example, are said to be necessary without qualification for an animal, not because they are required in every way and in every state. In the mother's womb, when an animal is first generated, it needs neither food nor breathing. Nevertheless, these are called necessary without qualification for an animal because they are required not for some added adornment or benefit, but for the animal's very being—not for its initial generation, but for its preservation and nourishment.

We say that Logic is necessary for the speculative sciences, not for the practical sciences, because practical sciences concern only the rightness of an operation, internal or external, and not the investigation of truth itself. Hence they need only prudence or art, which direct the goodness or rightness of things to be done or made, not Logic, which directs only the rightness of reasoning about truth.

By this conclusion we reconcile the opposed opinions concerning Logic's necessity. Some think Logic is only useful and not necessary without qualification, such as the Coimbra commentators, Prooemium, q. 6, art. 2, and others; others think it is necessary without qualification in every way, just as a universal cause is required without qualification for every action of a particular cause, such as Araujo, Metaphysics II, q. 3, art. 3, and others.²

We say, however, that Logic is necessary without qualification, speaking absolutely, but not in every way and in every state of any science. For something can be said to be such without qualification either because it is such absolutely and without an addition, or because it is said to be such in every way and under every consideration, as St. Thomas aptly observes in Summa theologiae III, q. 50, art. 5. What is such without qualification in the first sense admits of some latitude, and can be called necessary or such without qualification even though it is not necessary in every way and in every state. On this conclusion see the Carmelite Course, introductory disputation, q. 7.

THE FIRST PART, then, of the conclusion—that Logic is not necessary without qualification, that is, in every way, for the other sciences—is clear from this: Logic is required for the other sciences only as an art and instrument for acquiring them. The effect of an art does not depend on the art in such a way that it cannot be produced in some manner, at least imperfectly, without it. As the Philosopher says, “a person learning an art performs an action of the art without the art.”³ St. Thomas explains this at the end of his lecture 7⁴: “a person can in some way enter into an act of science and virtue before having the habit of science and virtue; once that habit has been acquired, he acts perfectly.” Indeed, if this were not so, the arts and sciences themselves could not be acquired through our acts, since at least the first acts by which they are acquired cannot proceed from the art, given that they generate it. Likewise, some demonstrations do not necessarily depend on Logic, at least those that generate Logic's first demonstration. Although those demonstrations do not exist without the Logic generated through them, Logic is not required for them; rather, they give rise to it. And if a demonstration is made in the subject matter of another science, it can be grasped and convince the intellect of someone who does not possess Logic. That person will then acquire the habit of the science to which the demonstration belongs, but not the habit of Logic, whose precepts he is not then being taught.

Finally, for this part we should consider St. Thomas's teaching in Metaphysics VII, lect. 8⁵, Summa theologiae I, q. 117, arts. 1 and 2, and Against the Gentiles I, chapter 75. There he distinguishes two kinds of art: “In some materials there is no active principle that produces the effect of the art: wood and stones, for example, have no active power moving them toward the construction of a house, which is the effect of the house-building art. Sometimes, however, an art works in material that has a moving principle for producing the art's effect, as is clear in medicine, because in a sick body there is an active principle for health. Nature never produces the effect of the first kind of art; it is always produced by art. But the effect of the second kind is produced by art and sometimes by nature without art.” So St. Thomas. Since Logic concerns directing the intellect's operations, and the intellect contains a moving principle for proceeding scientifically, just as the body contains a principle for health, an effect of Logic's art can sometimes be produced without the art. Thus Logic is not necessary without qualification for every demonstration and science, in every state and manner.

THE SECOND PART, namely, that Logic is required without qualification for science's perfect state and its preservation, is drawn from St. Thomas. In On Boethius's De Trinitate, q. 6, art. 1, second question, ad 3⁶, he says that necessity requires us to begin learning with Logic, although it is not easier than the other sciences, because the other sciences depend on it. And in Metaphysics II, final lecture⁷, and Posterior Analytics I, lect. 1⁸, he says Logic is ordered toward proceeding easily, promptly, and without error. It is clear that proceeding without error is not merely useful but necessary without qualification for the very being of the other sciences. It is also clear that the intellect's bare potency, unaided by art, cannot recognize every defect in inferences or scientifically discern the soundness of any inference, since many things are not known by natural light but are gathered by reasoning. Many things concerning knowledge of propositions that are per se and of necessary connections also depend on Logic's principles and precepts: for example, knowledge of the categories, in which essential predicates are arranged; of the predicables, which set out the modes of essential and accidental predication; and of the modes “per se,” “of every,” and “according to itself,” along with other matters taught in the Prior Analytics and Posterior Analytics. On these depends the discernment of necessary or contingent matter and of valid or defective inference. Therefore, the intellect cannot reach science's perfect state, in which it avoids all these errors and extends to its various conclusions, except through some principle added to it that teaches this artful mode of proceeding. Just as an animal in its perfect state—that is, when it nourishes and increases itself—needs food as the matter of nourishment, and digestion and assimilation of food, so for the nourishment and extension of the sciences, which must take place through many conclusions and various inferences, the intellect needs food, namely, species, but species that have been digested, assimilated, and arranged artfully for inference; otherwise it will not draw conclusions scientifically. The art of Logic provides this.

YOU WILL SAY: This is not necessary for being without qualification, but for better or more perfect being, because the being of the sciences is presupposed, just as the being of an animal is presupposed by food, which is required only for something added to the animal's being. Therefore Logic is not necessary without qualification, that is, for being.

The reply is that although Logic presupposes being, it is not said to be required for something added to being and, as it were, extrinsic to it, but for the continuation and preservation of being itself, so that it is not lost. For something to be required for a thing's being, and not for something added to it, is sufficient for its being necessary without qualification, even if it is not required for every state of that being. Food, for example, is not required for a human being's being during generation, but it is required for its preservation.

THE OBJECTIONS ARE ANSWERED.

First it is argued: Many demonstrations can be made without Logic; therefore Logic is not required for science's being, even in its state of preservation.

The antecedent is proved: many conclusions in a science can be demonstrated by the four moods of the first figure, which are known by natural light itself and not through the reasoning of Logic's art, since other conclusions are reduced to them as principles. It is also clear that Logic itself was first learned by natural light, without some earlier acquired Logic. Therefore the art of Logic is not required for science's very being, even as it extends to more conclusions, which is its perfect state.

THE REPLY: The antecedent is denied. Anyone who forms demonstrations without Logic, even if he does so in the four first moods of syllogizing, is always said to have science in an imperfect state, because without Logic one cannot arrange the several matters and conclusions of a science so clearly as to reduce them all to the first moods of syllogizing. Indeed, to perform this task one must be most perfectly practiced in the science and especially well versed in Logic's precepts. Nor can one similarly defend oneself against oppositions by discerning defects and weaknesses in the inferences used to attack one, or defects in definitions and divisions, and so on. Without this, however many demonstrations are made, they always remain in a weak and imperfect state. Logic itself, when first discovered, was discovered imperfectly by natural light, as were all the other arts. Later, in its perfect state, it helps itself and preserves itself just as it helps the other arts; thus no other Logic is necessary, because Logic suffices for itself.

Second it is argued: Natural light itself has sufficient power to acquire any demonstration taken separately; no final demonstration can be identified beyond which it is unable to proceed. Once a demonstration has been acquired, natural light's power is not diminished but rather increased. Therefore it will be able to proceed to a second and all the others without Logic, although less conveniently.

THE REPLY is that in arguments which move from a divisive enumeration of things a power can do to a complete and integral enumeration, a fallacy of accident or a defect of supposition is commonly committed. Each operation is counted separately, while the mode of operating through continuation and extension from one thing to another, and defense against opposing views, is omitted. Yet the whole collection is inferred, and that collection includes this mode of continuation or extension even though it was not counted. This cannot be done by limited powers unless they receive help from elsewhere. Although the intellect's power is not diminished by making one demonstration, because of its limitation it cannot continue all these operations and defend itself against opposition unless aided by some art. Thus, even though this enumeration seems to be made conjunctively by the word “and”—saying, “It can do this and it can do that,” and so on—in sense it is disjunctive. To be able to do this separately and divisively, and that separately, is the same as being able to do this or that disjunctively or divisively. But a distributive conclusion cannot be drawn from a disjunctive enumeration. For this reason we do not identify a single point beyond which the intellect cannot proceed separately and divisively. Rather, in this enumeration the limit it cannot reach is the whole collection, or the entire range of perfect power; it cannot reach that, although it can reach the imperfect or divisive range.

Finally it is argued: Logic contributes an artful mode of proceeding to all the sciences, as is clear from the Philosopher in Metaphysics II⁹, St. Thomas there, final lecture¹⁰, and Metaphysics IV, lect. 4¹¹. Therefore Logic is related to all the sciences as a universal cause. But a universal cause is required without qualification for every operation of a lower cause, just as if the motion of the heavens ceased, all lower motions would cease. Therefore Logic is required without qualification, that is, in every way, for every artful demonstration. If any demonstrations are made without Logic, they will not be artful or resolved up to the first principles.

THE REPLY is that Logic is not a universal cause primarily and in itself, but an instrument assisting the principal agent, which is the intellect. St. Thomas teaches this about every art in Summa theologiae I, q. 117, art. 1. An instrumental universal cause is not necessary without qualification in such a way that no effect of art can be produced without it, especially when that instrument is virtually contained in the principal cause itself and is derived from its principles. In place of the instrument, therefore, the principal cause can make up for the art's deficiency and produce the art's effect without the art. The heavens, however, are not a cause in the manner of an art or instrument, but a principal and universal cause, though moved by another, higher cause. As for the added point about resolution to first principles, the reply is that some resolution to first principles and some soundness of inference can be so per se evident that it can be grasped without art, although only in the imperfect state described above. All the other arts and sciences likewise had an imperfect state when they were first acquired.

There is no need to linger over explaining what is understood by the name “science”; it is clear that it means a habit acquired through demonstration and inclining one toward demonstration. Demonstration signifies a certain and evident proof of some truth. Although this certainty and evidence require resolution as far as first principles, which are perhaps found in very few cases and concerning few subjects, this is not due to a defect in science but to a defect in those who know. For most know only with imperfect, almost subalternated science, because they believe principles handed down by another science rather than resolving them within it.

LET THIS, THEN, BE THE CONCLUSION: Logic is truly and properly a science, and at the same time an art, though a liberal one.

Hardly anyone doubts this conclusion, although some have wished to say that Logic is not a science but a mode of science. St Thomas plainly calls it a science in Metaphysics IV, lect. 4¹, and Summa theologiae I–II, q. 57, a. 3, ad 3 and a. 6, ad 3. Likewise he calls it an art in Posterior Analytics I, lect. 1² and Summa theologiae II–II, q. 47, a. 2, ad 3. Finally, in Opusc. 70, q. 5, a. 1, ad 3³ he says that “among the other sciences those are called arts which have not only cognition but some work that immediately belongs to reason itself, such as forming a syllogism and an utterance, counting,” and so on.

THE FIRST PART of the conclusion is proved because Logic has demonstrative acts; therefore it is a scientific habit.

The consequent is evident, and the antecedent is still more evident, because Logic resolves conclusions into indemonstrable first principles. For example, when it proves that contradictories cannot be true together from the principle “Everything either is or is not,” it shows that two contraries cannot be true together, since that would entail that two contradictories were true together; it shows that a syllogism in Darii concludes correctly, because “to be said of every” is perfectly preserved in it, and countless other cases.

THE SECOND PART is proved in the same way, because the definition of art applies to Logic: art is called “the right reason of things to be made.” Hence two things are required for art. First, on the side of matter that can be directed and formed, it must not be wholly determined but possess some indifference; otherwise it could not receive regulation and art, just as acts of seeing and hearing cannot be directed by art. Second, on the side of form, which functions as a directing rule, regulation must proceed by certain and determinate ways. If the means were not certain and determinate but contingent, they would be directed not by art but by prudence, which directs by deliberation rather than art, since it has no certain and determinate rules, but discretionary and prudential ones suited to the circumstances that arise, as St Thomas teaches in Summa theologiae II–II, q. 47, a. 2, ad 3. Not only external works, called “things to be made,” fall under the regulation of art—these are the concern of the so-called mechanical arts, since external works are more servile and subject to command—but also internal works, which are freer and less servile; hence the arts directing them are called liberal arts. In the actions of both kinds there is matter that can be directed by certain and determinate rules, because there is indifference as to whether they are done well or badly, with or without error.⁴

The second part of the stated conclusion is proved from this: the remote matter, or matter that can be directed by Logic, consists in cognitions or operations of the intellect, which, insofar as they attain objects, can proceed with or without error and thus have sufficient indifference to be directed and formed by right disposition and ordering. On the side of form, or rules by which Logic orders, it has certain, determinate and immutable rules, as is clear from what has been taught in the Summulae and what we shall teach in this work, especially in the books of the Posterior Analytics. Therefore Logic has everything required for the nature of an art, and at the same time is a science because of the immutable certainty of its regulation, although its remote matter is indifferent.

THE ARGUMENTS ARE ANSWERED.

Against the first part of the conclusion it is argued that Logic is a mode and instrument of knowing; therefore it is not a science.

The antecedent is a common saying and is taken from Aristotle, Metaphysics II, near the end⁵, and St Thomas, Opusc. 70, q. 5, a. 1, ad 2⁶, where he says that “Logic is not placed under Philosophy as a principal part, but as something subordinated to it, insofar as it supplies its instruments to speculation.” The consequent is proved because an instrument does not have the same primacy as its cause or effect, as is clear in the case of a saw, a brush, and other things, which are not of the same nature as the thing they make or the agent that moves them.

THE ANSWER IS that Logic is called a mode and instrument of knowing objectively, not formally. For it treats as its object the mode of knowing and the instruments necessary for the other sciences, such as syllogisms and propositions; on the side of this object it differs from the other sciences, because they treat things, while Logic treats the mode of knowing. Since the mode of knowing must be known before things, Aristotle therefore said it was absurd to investigate both at once. In the same way St Thomas said that Logic is not contained principally under Philosophy, but as something subordinated to it, namely, as concerning the mode of knowing things, which is a less principal object. The argument’s consequent is answered as follows: first, Logic is not an instrument of the other sciences but of the intellect itself, which uses Logic as an instrument for directing the other sciences. Thus it follows only that Logic is proportioned to the intellect, not to the sciences. Further, it is not incompatible for an instrument to be of the same nature as the thing effected, though this is not always necessary, as one hammer makes another.

Second, it is argued that it is probable that teaching Logic and using it are one and the same habit, as is said in the final article. Therefore the habit of Logic elicits acts of opinion, as is evident in Logic as used, which proceeds topically and probabilistically, as is clear from St Thomas, Metaphysics IV, lect. 4⁷ and Opusc. 70⁸. But a habit that elicits acts of opinion cannot be science. Therefore Logic is not science.

It is confirmed because a being of reason cannot specify a real science, since a being of reason is not per se knowable and consequently not per se scibile, nor does it have true causes through which it may be known or properties that may be known of it. But a being of reason is the formal object of Logic, as we shall say in the next article. Therefore Logic is not truly a science.

THE ANSWER IS that this argument will be treated below, in the final article. For now we say that Logic, insofar as it is used, has an opinionative act not by reason of its formal motive, since it does not rely on fallible and contingent principles, but by reason of the consequent effect: it directs a mode of proceeding opinionatively in topical and tentative disputation, which is not fully resolutive. Hence it has an opinionative act directive rather than elicitive; or, if it elicits one, it does so secondarily and not principally. It is not incompatible, then, for a scientific habit to have an opinionative act secondarily and consequentially, in relation to the topical and opinionative rules that it teaches scientifically.

The confirmation will also be answered in the next article, where we shall show that a being of reason has sufficient knowability and objective truth, grounded in reality and necessarily connected, as science requires—not because it has truth subjectively and transcendentally as a true being, but objectively, as the object of a science.

Finally, it is argued: the nature of art is incompatible with science; therefore one or the other does not apply to Logic.

The antecedent is proved: art deals with singular and contingent things and is in the opinionative part of the soul, as St Thomas says in Summa theologiae I–II, q. 57, a. 4, ad 2, whereas science concerns universals and necessary things and is in the demonstrative part. Likewise, art proceeds compositionally and practically, while science proceeds resolutively and speculatively. Hence St Thomas, Metaphysics I, lect. 1⁹, distinguishes art from speculative reason and places it in the practical part of the intellect.

It is confirmed because the liberal arts are called arts by a certain likeness, as St Thomas says in Summa theologiae I–II, q. 57, a. 3, ad 3. Therefore Logic is not simply and properly an art.

THE ANSWER IS that art is said to concern singular and contingent things on the side of its application to a work, or on the side of its remote matter, which has indifference—not on the side of the rules by which it directs, for these are certain, determinate and universal. Hence art is numbered among the intellectual virtues in Summa theologiae I–II, q. 57, although these do not deal with contingent truth but with what is necessary, to which falsity cannot adhere; otherwise they would not be virtues, as St Thomas teaches in Nicomachean Ethics VI, lect. 5¹⁰. Art is said to be in the opinionative part of the soul either on account of the mechanical arts, or because of its application to a work, or because of the indifference of its remote matter that can be directed—not on account of direction and regulation, in which respect art is an intellectual virtue, something that does not belong to an opinionative habit. Nor is it of the nature of art to proceed compositionally and practically; when its work is speculation, it directs not by composing but by resolving, as will be explained further below.¹¹¹² And when St Thomas distinguishes art from speculative reason, he is not speaking of liberal art but of that which is art in such a way that it is not science.

The confirmation is answered by saying that liberal arts are called arts by likeness on the side of matter that can be directed, not on the side of the directing reason. Since the matter of a liberal art is an internal work of reason, which is less servile, it is consequently less subject to the command and direction of art than the work of a mechanical art, which is wholly servile. Yet on the side of the directing rule, liberal and mechanical art apply univocally. In any case, since we do not say that Logic is an art in just any way, but a liberal art, it has the nature of art precisely in the way that applies to liberal arts.

TWO THINGS MUST BE PRESUPPOSED, which indeed pertain more properly to another place, but must be touched on briefly for the present difficulty.

The first is that there are beings of reason, which must be treated in the following question. By “being of reason” we understand that which cannot exist in itself and apart from the intellect’s consideration, yet can be considered by the intellect. That we consider many things that do not exist is too evident to need proof. But because the intellect considers everything in the manner of a being, things that are considered but do not exist are called beings of reason, “existing, as it were, only by reason’s benefit and through consideration.” Sometimes such a being of reason is purely fictitious, as when we imagine something by fabricating it without any foundation in reality, for example, when I form a chimera, a golden mountain, and similar things. At other times it is not purely fictitious, but has a foundation in some real being that can be known in such a way that, from this mode of knowing, something is attributed to it or follows from it that is nevertheless not in reality—for example, when I know God in relation to creatures, or know darkness in the manner of a form affecting the air, although in reality it is not a form but the absence of a form. Things fabricated in the first way are called beings of the reasoning reason; those in the second way are called beings of the reasoned reason, that is, founded in the thing known.

The second thing we presuppose is what we mean by the name “formal object.” A formal object is that formality, account, or determination through which something is attained by a habit or power. For in the case of things that are objects of some habit or power, it is clear that there is both the thing attained and the account or determination by reason of which it is attained. Indeed, several formalities may be required for something to be attained; one determines another, and with respect to what it determines is called its formal aspect. This formal account is usually called the account that is attained or the account of attaining; and if it is the ultimate account, by which the others are determined, it is also called the account under which, because the others are contained under it. For we see a stone as the thing seen and the material object, but we see it by reason of color, which is the account by which the stone pertains to sight rather than touch or another sense. Color, in turn, is determined and formed by light, by reason of which the object is ultimately constituted as visible. There is also another account under which, on the side of the power, namely the power or determinate light of knowing itself. We do not treat of that here, but only of the objective formal account. Therefore, when we inquire whether a being of reason is the formal object of Logic, this is the same as asking whether all the things and subject matters treated and directed by Logic pertain to Logic by reason of something that is a real being or a being of reason; and, if it is a being of reason, which one it is.

With these points established, two things are certain in this matter, and the whole weight of the difficulty lies in one point.

First, it is certain and beyond logical controversy that Logic treats at least some beings of reason, which are found in and attributed to the things known and to the words that Logic uses as instruments—for example, the account of genus and species, the account of predicate and subject, and other similar intentions.

Second, it is certain that Logic does not treat every being of reason in its full breadth, such as privations, negations, and other things that are altogether fictitious. It treats only those relations founded in things insofar as they are ordered and known by reason, and these are called logical intentions. These logical intentions relate both to objective concepts, formal concepts, and words, but in different ways. They pertain to things known as foundations in which they are founded and which they denominate, just as a known animal is denominated a genus and a man a species. They pertain to formal concepts and acts of the intellect as operations by which these intentions are formed; therefore, once such intentions are formed, the operations of reason are also denominated as proceeding correctly and in order. They pertain to words as signs or instruments that externally express concepts ordered in this or that way.

Some, then, attending to the things known in which those intentions of reason are founded, simply say that the formal object of Logic is a being of reason, namely a second intention, because it is only by reason of that intention that such things pertain to Logic. This is the common view among Thomists. See Carmelus, Course, disp. 1, q. 2, § 3. Others, attending to words and concepts, say that Logic, insofar as it regards significant words, treats second intentions, but insofar as it regards the operations of the intellect, treats something real, as may be seen in Martinez, q. 4 of the proem. Finally, others, attending only to the operations of the intellect, which Logic directs first and per se, simply say that it treats something real. See Fonseca, Metaphysics II, ch. 3, q. 1, sect. 5; Suarez, Metaphysics, disp. 54; Master Cabero, tract. 1, disp. 1, dub. 2.

THEREFORE, THE POINT OF THE DIFFICULTY IS this: which of all these is formal with respect to Logic? Is it the objective concepts under the account of the intentions they found, or the formal concepts or words under the direction they receive from Logic? And is this direction something real?

RESOLUTION

According to the thought of St. Thomas.

LET THERE BE ONE CONCLUSION: The matter that can be directed by Logic, as an operation, is something real. — The matter that can be denominated by logical art as an object or thing known is anything knowable through those operations of the intellect, whether real or of reason. — But the form, both with respect to the operation that can be directed and with respect to the thing known, under which they pertain to Logic, is something of reason, not purely fictitious, but having a foundation in things as a second intention.

This¹

The conclusion is in keeping with the mind of St. Thomas. Among other things, three passages may be weighed in its favor. The first is in the Proemium to the Ethics,² where he says “that order is related to reason in four ways. For there is one order that reason does not make but only considers, as is the order of natural things. Another order is one that reason makes by considering its own act, for example, when it orders its concepts among themselves and the signs of concepts, which are significant words. A third order is one that reason makes by considering the operations of the will. A fourth order is one that reason makes by considering external things of which it is the cause, such as a field and a house. The order that reason considers but does not make pertains to natural philosophy; the order that reason makes by considering its own act pertains to rational philosophy (that is Logic); the order of the actions of the will pertains to the consideration of moral philosophy; and the order that reason makes by considering external things pertains to the mechanical arts.” See: St. Thomas posits as the object of rational philosophy, or Logic, the order that reason makes by considering its own act. This order is certainly not real, because a real order can indeed be considered through cognition, but cannot be made by consideration alone without some other real external act. For this is what characterizes a relation of reason: it is made or attained through consideration alone.

The second passage is in the first book of the Posterior Analytics, lecture 20,³ where he says “that because reason has to deal with all things that are, and Logic concerns the operations of reason, Logic too will concern what is common to all things, that is, the intentions of reason that apply to all things.”

And third, most clearly, in Metaphysics IV, lecture 4,⁴ he says: “Being is twofold, namely a being of reason and a being of nature. A being of reason is properly said of those intentions that reason devises in the things considered, such as the intention of genus and species and the like. These are not found in the nature of things but follow upon reason’s consideration. This kind of being, namely a being of reason, is properly the subject of Logic.”

SOME RESPOND that St. Thomas is speaking of an object per accidens; or, if he is speaking of an object per se, that he takes “being of reason” to mean the very work of reason insofar as it has dialectical art. But against this: the holy Doctor says that such a being of reason is properly the subject of Logic; therefore he is not speaking of an object per accidens or material object. For he immediately adds that this is every being of nature, insofar as it is subjected to intelligible intentions. He also says that those intentions with which the logician deals are not found in the nature of things, whereas acts of the intellect are found in the nature of things. Therefore, either the work of reason, insofar as it has dialectical art, is formally a being of reason not found in the nature of things—and thus we have what we seek, since according to St. Thomas this is the formal object of Logic—or it is found in the nature of things as such, which contradicts St. Thomas, who says it is not found there.

Others reply that St. Thomas is speaking of a being of reason, that is, an extrinsic denomination, which is the formal object of Logic. But against this: St. Thomas says that Logic treats intentions that reason devises in things considered and that are not found in the nature of things. But those extrinsic denominations either are found in the nature of things insofar as they are extrinsic, in which case Logic does not treat them, or they are not found there but are formed by reason, in which case they are beings of reason, as we maintain.

Finally, others say that St. Thomas is speaking of significant words, which the logician treats as means or instruments, and that the intentions of these words are something of reason. But St. Thomas clearly teaches the opposite, because he speaks of intentions that follow upon the operations of the intellect themselves and that reason makes in its own act, or devises in the things considered, as is clear in the passages from Metaphysics and Ethics cited above, and in Opusculum 42, ch. 4.⁵ Therefore, he is not speaking only of intentions of words, but also of intentions of things known, such as genus, species, and so on, or of those attributed to the proper operations of the intellect themselves.

Therefore, there can be no doubt about St. Thomas’s mind: he posits a being of reason as the formal object of Logic, just as he posits the things known and ordered concepts themselves as its material object, as is clear in the cited passages, in Opusculum 56,⁶ and Opusculum 70, final question, art. 1, ad 3,⁷ and in the first book of the Posterior Analytics, lecture 1.⁸

The basis of the conclusion is that every reality that can be found in the object of Logic is either an act of the intellect by which things known are denominated, the thing itself understood and represented, or something real added to and accruing to concepts or objects known through the ordering of Logic.

The first two pertain, according to their reality alone, to the material object of Logic, because real sciences deal with things known insofar as they are things, and philosophy deals with concepts insofar as they are real perfections of the intellect. Logic, then, formally treats them only insofar as they are ordered artificially. For example, it is per accidens and materially relevant to Logic that the intention of genus is in a tree or a stone; Logic does not treat the nature of the stone or tree itself, but the intention or formality of genus found in all of them.

If the last two are proposed, we ask: what is it that accrues to concepts or objects through Logic’s ordering? If it accrues to the objects themselves as known, it is a second intention and something of reason; for what belongs to things known does not belong to them as they are in reality, and so is not something real but something of reason. If, however, it is only an extrinsic denomination by which the things themselves are denominated as known in this or that way, and which does not supervene on things already known, this is objectionable for two reasons. First, this denomination is not something artificial, but follows naturally and without any art or comparison, as the denomination “seen” follows upon vision in the object. Second, many logical intentions belong only through comparing and relating one thing to another and presupposing that the thing is known and apprehended, such as the order of superior to inferior, subject to predicate, and composition in a proposition and syllogism. Therefore, these are not extrinsic denominations of something known, but something belonging by reason to things known.

If instead it is something accruing to the concepts or acts themselves as they are elicited by the intellect with some influence and ordering from Logic, this too is objectionable. For this ordering impressed on concepts or acts is not something entitative in relation to itself, but something representative or signifying an order toward objects. Logic does not care about the real entity of concepts, nor do concepts need Logic’s ordering for their elicitation, since they are natural and flow naturally from the power; once the species and the power or faculty are posited, they need no art for this emanation. Therefore, the order toward artificially ordered objects is indeed something real in concepts or acts, namely representation, by which they naturally regard objects even if those objects are not real. Yet this order is not the formal object of Logic, but at most an effect that Logic directs in other sciences, so that through Logic’s showing, they may tend and be ordered toward an object disposed in a logical way. But the impression of a higher power or art upon an inferior one, so that it may be ordered to the superior’s object or end, is only an effect of the superior, not its formal object. This is clear in architectonic arts, which direct inferior arts to their end, and in a higher angel illuminating an inferior one; for neither has as its object the act of the inferior that it orders or illuminates. Thus the formal object of such a higher light is not the inferior act that is illuminated, but the object by which the inferior proposition is illuminated. The reason is clear: when a superior power or art impresses upon an inferior and orders it to its own end, the superior is already presupposed to have an end and a specifying object of its own, to which it directs and orders the inferior. Therefore, what properly specifies the superior is not the impression and ordering of the inferior toward such an end, but the end itself, which is the superior’s object and whose order it effectively communicates to the inferior. Similarly, when Logic orders and illuminates the other sciences with respect to the artificial manner of reasoning, it will not have as its formal object the very acts of the other sciences as they tend and are really ordered toward their own ordered objects. Rather, what Logic considers in the object known and proposes to the other sciences to follow will be its formal object. This ordering of objects is certainly a second intention in the objects.

SOME RESPOND that Logic per se regards only the placement and arrangement of concepts, so that one is a predicate and another a subject, and so forth; but that something of reason results from this arrangement is not per se considered by Logic. Others say that Logic directs the intellect to elicit acts whose objects are ordered according to logical intentions; thus the immediate object of Logic is these acts, while the objects of these acts are something of reason insofar as they are ordered, and this is the remote object. Finally, others say that because the operations of the intellect are really perfected through Logic—otherwise the logician would not be more perfect in reasoning than an untrained person—it therefore has some real perfection as its object.

But against the first solution: the placement and arrangement of concepts is not a spatial arrangement, like stones in a house; it is the representation of and tendency toward things correctly placed and ordered among themselves. For concepts are not said to be ordered entitatively, as it were, but representatively and with respect to the objects with which they deal. Therefore, Logic principally regards the ordering of objects, and formally regards the tendency and representation of concepts as a means of attaining these ordered objects.

But against the second solution: Logic does not teach how to elicit acts as regards their entity, but how they are to be arranged artificially. And because an artificial arrangement is found in acts only insofar as they attain ordered and arranged objects, directing the intellect through Logic to elicit its acts artificially is the same as proposing the ordered objects themselves, about which the acts of the sciences are elicited. Thus Logic attains first and per se the second intentions of objects; it communicates to acts, effectively or by way of direction, the order of acts to those intentions.

The third solution, finally, misses the point. We do not doubt that attaining an object insofar as it is correctly ordered is a real perfection of cognition and science; but this is not the formal object of Logic, but the means by which the objects ordered by Logic are attained. This ordering in the objects themselves is something of reason and a second intention. But the acts’ attaining and tending toward such objects as ordered in this way is a real tendency and perfection, derived from Logic’s direction only effectively or by way of direction; for cognition and attainment of beings of reason is a real perfection in cognition.

BUT YOU WILL ASK TWO THINGS: First, is a second intention the formal object of Logic as an account under which or as an account that is attained? I answer that it is the account that is attained. For many properties are demonstrated of second intentions in Logic, such as predicability of the universal; therefore, it is a thing known through the science of Logic and consequently pertains to the account that is known. Hence St. Thomas calls these intentions the subject of Logic in Metaphysics IV, lecture 4.⁹ It is clear, however, that the subject is the thing that is known. The account under which, as in other sciences, is taken according to abstraction from matter, which supplies a mode of intelligibility under which a thing can be known in different ways according to how it is abstracted from matter, as will be explained more fully in Philosophy and in the final question of the Posterior Analytics.¹⁰ The object of Logic, however, which is a being of reason, has an abstraction like that of Metaphysics, namely from all matter—not by purifying actuality from matter, but by negating all matter.

The second question is: among the objects with which Logic deals, which is its principal object? I answer that the syllogism, which is formed through the third operation, is the principal object of Logic; and among syllogisms, demonstration is principal as regards matter. The reason is clear, because, as St. Thomas teaches in Perihermeneias I, lecture 1,¹¹ and Posterior Analytics I, lecture 1,¹² all three operations of the intellect are so related that the first and second are ordered to the third as their principal end, in which reasoning and discourse are perfected; these are correctly arranged through the syllogism and resolved with certainty and firmness through demonstration. Since, then, the science of Logic is properly and essentially directive of reason, that is its principal object in which reasoning and discourse are principally found with certainty and without error. But error occurs either through a defect of form or through contingency in matter. Therefore, as regards form, the principal object is a syllogism correctly arranged; as regards matter, the principal object is demonstration, in which the process of reason is found to be without error both as regards matter and form. Nevertheless, Logic also treats per se what pertains to the other two operations, though less principally, as we showed in Summulae I, q. 1, art. 1.

OBJECTIONS ARE RESOLVED.

First it is argued: A being of reason cannot be the object of a science first and per se; therefore the conclusion is false.

The antecedent is proved as follows. A being of reason is not per se and formally knowable, because it is not per se a being and thus does not per se ground knowability; therefore it is not per se knowable. Further, it has no properties caused by itself about which it could treat, since it causes nothing; nor does it have causes through which it could be known, since it is not caused. Therefore, no science is given directly and per se of such a being of reason.

The reply is that there is no science of a being of reason that has no foundation in or order toward a real being, as with a chimera and similar things. But a science per se can be given of a being of reason that has a foundation in a thing or an order toward a real being, just as sciences treat privations, privation is one of the natural principles in philosophy, and theologians treat many relations and distinctions of reason.

And to the reply: “It is not per se a being; therefore it is not per se knowable.” The consequence is distinguished. If “per se” means subjectively, it is not knowable; I concede. If “per se” means objectively, I deny; that is, it is not an entity in which knowability inheres as in a subject, yet it is an object attainable by some knowability. For something to be simply and univocally knowable, it suffices that it be per se attainable objectively by a power, insofar as the object grounds a necessary connection. Something can likewise be called possible in two ways: intrinsically, through the potentiality it has subjectively and materially to receive something in itself or to come to be in itself; or extrinsically, because as an extrinsic object it is related to an effective power, as St. Thomas teaches in the First Part, q. 9, a. 2. Yet both are simply and univocally possible. Similarly, something can be knowable either by reason of its intrinsic entity, which is the subject of knowability, or because it can be known objectively and can perfect the intellect objectively, as in the case of what is founded in a real being, even if it has its being from the intellect as though effectively; this suffices for it to be simply knowable. St. Thomas explains the Philosopher in this way in Metaphysics VII, lecture 4,¹³ when the Philosopher¹⁴ says that what is not knowable is knowable in a qualified sense. St. Thomas explains: “By derivation, because we can know of what is not knowable that it is not known; and likewise of what is not a being, because it is not.”

And to the second proof it is said that a being of reason does not have properties really caused, but it does have properties founded, following upon, or connected with it; nor does it have real and efficient causes of itself, but it does have foundational and formal causes that ground a true and necessary connection and truth. This is to have, as it were, causes metaphysically, not physically.

Second it is argued: Logic per se regards the operations of the intellect as things to be directed. But some real perfection accrues to these operations from Logic’s ordering; therefore it has something real that it regards formally as its object.

The major premise is clear and often asserted by St. Thomas in the passages cited above. The minor premise is proved as follows. First, understanding and reasoning are more perfect in a logician than in an untrained person who does not know the precepts of Logic. Second, it is proper to demonstration to generate science insofar as demonstration is correctly arranged; but it receives this arrangement from Logic. Third, prudence and the other arts direct their actions according to right morality and art, all of which is something of reason; yet because the directed actions are something real, prudence and the arts are said to have something real as their formal object. Therefore the same should be true of Logic.

The reply is: Presupposing what we said in the conclusion—that the matter directed by Logic is the operations of the intellect, which are arranged artificially, not by receiving something artificially made entitatively in themselves but representatively—not because representation itself is artificial (for concepts represent naturally), but because they attain objects artificially ordered by logical intentions, and thus the operations are denominated artificial by their object.

Hence it is said, in reply to the argument’s minor premise, that although the order and tendency of concepts toward correctly ordered objects is something real, this tendency is not the formal object of Logic, but that by which the intellect attains the objects ordered by Logic.

To the first proof it is said that the act of understanding is more perfect in a logician than in an untrained person in attaining and representing ordered objects better, just as an act of understanding that discerns relations of reason, privations, and other beings of reason is more perfect than one that does not discern them. It does not follow from this, however, that the formal object of Logic is that representation and tendency of cognition; rather, it is the ordering of the objects with which that cognition deals.

To the second proof it is said that the effective and physical causality by which the act of demonstration generates habitual science does not pertain per se to Logic as directing, but to the science that is directed. This effective generation belongs to that science by reason of the real acts of which demonstration consists. It pertains per se to Logic to consider in demonstration the correct syllogistic arrangement and suitability of the matter—that is, that the propositions be necessary and per se and correctly arranged. These are conditions required on the side of the object so that the scientific process may be ordered, not the very effective power of science.

To the third proof, it is said first that there is an evident difference between the arts that deal with external matter and Logic: those arts do regard an order formed and made by the intellect and producible externally through an executive power—for example, that pieces of wood be arranged in a certain shape, position, and placement. This whole is something real in itself, although it depends effectively on reason’s direction. Thus such artificial effects are not said to be something of reason objectively, but effectively: they proceed from reason as the efficient and directing cause of their production, but their being does not consist in objective formation or in being known objectively. Logic, however, regards what is in the object, not by reason of an intellect moving toward execution, but by reason of an intellect dealing purely with objects known.

There is likewise a difference between prudence and Logic, although prudence deals with practicable things, which are interior acts. For prudence has two parts: one deals with judgment about things and deliberation; the other deals with command and precept, or application to things judged and deliberated about. It is not inappropriate for the act of judging or deliberating to deal formally with something of reason, that is, with the very objects ordered by the rules of law or right judgment. This ordering posits nothing real in the things themselves, but is a denomination or relation of reason. Nevertheless, it is not called a second intention, because it belongs to things not as known but as appetible under a moral rule. The act of commanding and prescribing, however, which is principal in prudence, as St. Thomas teaches in the Second Part of the Second Part, q. 47, a. 8, does not directly regard objects by ordering them—for law and reason order them—but directly regards the application of the will to elicit acts concerning ordered objects, since the principal practical difficulty lies in this application. Therefore, in its principal act prudence formally regards the eliciting of acts, which are something real, rather than the ordering of objects. But Logic does not have an act of commanding and applying the will or other powers; it only orders objects in their known being through second intentions. Once this ordering has been made or proposed, without any new difficulty or application of command, the intellect itself or the other sciences form their acts concerning objects ordered in this way. Thus Logic does not formally deal with the eliciting of acts, as practical command does, but with the ordering of objects known.

Finally, it is argued: Logic has as its object the mode of knowing, namely definition, division, and so forth; for it supplies these to the other sciences. But these are formally acts of cognition arranged artificially. Therefore these acts, insofar as so arranged, are the object of Logic and do not pertain to another science; but in this respect they are something real, namely acts of the intellect.

It is confirmed that even if no beings of reason resulted in relation to objects, or even before they resulted, Logic would still have to direct cognition; therefore it does not formally deal with a being of reason as a being of reason.

The reply is that there is no doubt that the acts of reason by which definition, division, and the other instruments of Logic are formed are real entities, having an order of natural representation and tendency toward objects. Logic adds nothing to the acts over and above this tendency in order for them to be called ordered; rather, the whole difficulty concerns the objects known, insofar as they are ordered, and this ordering in the objects is something of reason. As regards eliciting acts toward these objects, there is no difficulty for Logic to overcome, but only a natural representation for the intellect to produce. Therefore, that the acts are real as regards their tendency toward objects and representation, I concede; that they are real as regards the objects ordered through an intention of reason, I deny. This latter formally pertains to Logic, although that by which such an object is attained must be a real concept and act.

Nor can it be said that Logic regards this artifice only by connotation, but formally and directly regards the acts, because the formal account by which those acts pertain to Logic is this artifice. It is by reason of the artifice that these acts pertain to the art, not by reason of their real entity, which is subject to this artifice insofar as it representatively regards that artifice in the ordered object; for in this way they are something natural and are considered by natural philosophy.

In reply to the confirmation, it is said that even if intentions did not result as beings of reason formally and according to objective existence, Logic would still be given to consider their accounts at least on the side of their foundation. But if such intentions were given neither formally nor fundamentally, Logic would not exist. Likewise, on the opposing view, if there were no extrinsic denominations or artificial and real directability of the acts themselves, Logic would not exist, since it deals only with that. As a matter of fact, however, precisely because Logic directs its acts artificially, a second intention results in the ordered objects, because, as we shall say in the following question, art. 4, from St. Thomas, from the very mode of understanding one thing in relation to another there results a relation of reason.

When St. Thomas says that Logic deals with acts of reason to be directed, just as the art of the smith deals with the actions of the hand, in the first book of the Posterior Analytics, lecture 1,¹⁵ the meaning is clear: it deals with acts of reason as matter to be directed, while presupposing the artificial form as the formal account of this direction. As was said, this form belongs on the side of the object with which the act of reason deals, just as the formal object of the smith’s art is not the actions of the hand but the things made by the hands.

Many things are commonly handed down by authors in this context concerning the difference between the practical and the speculative, what praxis is, and whether it is found only outside the intellect or also in the intellect. None of these matters belongs to our present place; rather, merely so that the question’s title may be understood, it suffices to note the common difference between the practical and the speculative, which is taken from the Philosopher in De Anima III,¹ lect. 15, as cited by St. Thomas,² and in Metaphysics II, lect. 2,³ as well as Prima Pars, q. 79, art. 11, and q. 14, art. 16. It consists in this: the speculative regards truth so that it may be known, whereas the practical regards it so that it may be made and carried out in a work.

But since the very cognition of truth is also a kind of work, and conversely every work is also some truth, these things must be distinguished with great precision. For what effects a work in any way, or elicits an operation, is not called practical; rather, what directs toward a work, orders it by rules, and has it as its end is called practical. Thus not only must there be an elicited operation, but also an object or matter that, in its execution and in order to be brought about, needs rules directing it toward making, and not merely rules for knowing; for in the speculative and the practical, knowing and making are always distinguished. Nor is whatever cognizes truth in any way called speculative, but what intends only to cognize, not to make anything further, and directs not in order to make, but in order to know and escape ignorance.

Hence, for something to be speculative, its matter must either not be operable, as when someone considers God, an angel, or the heavens, etc., or, if it is operable, it must be apprehended not as operable but as knowable and as a certain truth. For something to be practical, however, its matter must be operable and must be apprehended in an operable mode. Thus, when the Philosopher distinguishes the practical and the speculative by their end, he is not speaking only of an end on the part of one who understands and actually acts, but of the end intended by virtue of the very principles and rules that a science uses. For if its principles merely manifest truth, as it were illuminating it and dispelling ignorance, it proceeds speculatively. But if they not only manifest truth but also direct toward its being made and established in existence, they are practical and order praxis, understanding “praxis” as a general name for the object of practical cognition. Hence speculative principles are called resolutive, because they regard truth only as it is resolved, in a knowable way, into its principles; practical principles, on the other hand, are called compositive, because they regard truth or being as something to be brought into existence. On this point see St. Thomas, Metaphysics II, lect. 2.⁴

Therefore, when we now inquire whether Logic is practical or speculative, the point of difficulty comes down to this: whether the formal principles by which Logic proceeds regard the truth it treats in such a way that they proceed purely resolutively, in the order of knowing; or whether they are ultimately ordered compositionally toward exercising and making some work beyond knowing itself, so that there is not only speculation of truth but also praxis; or rather, whether the very ordering toward knowing can be practical.

On this question the authors divide into three chief opinions.

Some consider Logic simply practical, because although it speculates about many things, it orders them all to a work, namely, the correct construction of a syllogism. Accordingly, this opinion designates the operations of the intellect as its practicable matter, and practical principles as the rules or precepts by which it teaches not only in general what the nature of a syllogism is, but also in particular how it is to be constructed. For this opinion see Fonseca, Metaphysics II, ch. 3, q. 2, sects. 3 and 4; and the Coimbra commentators, q. 4 of the proem, art. 5.

Others, on the contrary, make Logic simply speculative on the basis of a contrary argument: either because they think that no act of the intellect is praxis, or because, even if they admit that some act of the intellect, insofar as it is subject to the will, can be praxis, it is not praxis insofar as it purely regards an object under the aspect of knowability. Logic, however, does not immediately direct concepts themselves in their entitative being, but rather the objects, which it orders and arranges as required for proper speculation. This is the common opinion of the Thomists. See Master Soto, q. 4 here; Sanchez, q. 16; and the Carmelite Course, disp. 1 (proem), q. 6, § 2.

Still others finally think it is at once practical and speculative, because they say that the speculative and practical aspects are accidental differences in the sciences, or at least that Logic contains a composite, partial habit, one part speculative and the other practical. So say Father Vasquez, Prima Pars, disp. 9, ch. 1; Master Cabero, disp. 3, dub. 3; Martinez, q. 3; and others.

Nevertheless, we must say first: One science of the natural order cannot be at once practical and speculative, and consequently neither can Logic.

This conclusion is taken from St. Thomas, Prima Pars, q. 1, art. 4, where he acknowledges that the practical and the speculative constitute different sciences in philosophical disciplines, which is a sign of essential diversity. Likewise, in Ethics VI, lects. 2 and 3,⁵ and Prima Secundae, q. 57, he distinguishes science and wisdom from art and prudence as essentially diverse virtues, because the former are speculative and the latter practical. This may also be seen in opusc. 70, q. 5, art. 1.⁶

The reason is that the specific distinction of habits is taken from their formal object. In the sciences, however, the formal diversity of objects is reduced to diverse principles, from which one proceeds concerning one object or another, as St. Thomas shows from the Philosopher in Posterior Analytics I, lect. 41:⁷ “Just as,” he says, “the formal account of the visible is taken from light, by which color is seen, so the formal account of the knowable is taken according to the principles by which something is known.” The practical and the speculative, however, require diverse principles in the very formal account of knowing. For speculative principles proceed in a resolutive mode and tend only to manifest the truth according to its connection with and dependence on the formal principles of that truth; practical principles, on the other hand, neither resolve nor illuminate truth with respect to its formal principles and quiddity, as though abstracting from existence, but apply and order it toward bringing it into existence, and thus proceed compositionally. Hence the speculative regards the causes of truth abstractly and in themselves, whereas the practical regards them concretely and in a work, without abstracting from existence. Principles are never speculative except insofar as they are distinguished from and opposed to practical principles: they proceed in an opposite way, since they do not apply to a work. Thus practical and speculative principles differ more in their account of knowing and illuminating than do two speculative principles that constitute diverse species of science. But if they constitute diverse species in themselves, they cannot inadequately, as parts, combine to constitute a third species that is at once practical and speculative, even inadequately, as some say. Just as one science cannot unite two diverse species of science—for example, be at once Mathematics and Metaphysics, or something similar—so it is incompatible for specifically different things, being opposites, to be united inadequately to constitute one third thing, unless their opposition and difference are removed in some higher form, as I shall say shortly. For now, however, we are speaking only of sciences of the lower order.

How the practical and speculative aspects are united in THEOLOGY and other supernatural habits, as St. Thomas teaches in Prima Pars, q. 1, art. 4, Secunda Secundae, q. 8, art. 3, and q. 45, art. 3, is another matter.

We say briefly that in these habits the practical and speculative aspects of the lower order are not united as they are found in lower things, because these always differ in species, just as the vegetative power as found in a plant and in a brute animal is never united in one form. Nor can any specific differences be united in the order in which they are specific differences; that is self-contradictory, since insofar as they are specific differences they are opposites, and if they are opposites they cannot be united into one. But they can be united in something of a higher order, in which a more eminent form, in one superior mode, exercises what several lower forms exercise in diverse and opposed modes. It is otherwise with higher and lower grades or predicates, such as sensitive, vegetative, etc., which are united in some contracted form, as in a human being. These grades, however, are not opposed like species or specific differences; rather, they stand as a higher and a lower predicate, one of which contracts the other without being incompatible with it. The superior account of science in which the practical and speculative are united consists in this: these supernatural sciences attain God as he is in himself. In God himself, however, the principle of proper speculation and of practical ordering is the same, because he is necessary truth in himself and is also the rule of contingent things; thus, in a simple way, he unites the principles of speculation and praxis. This does not occur in other lights, which cannot by one manifestation simultaneously manifest a thing according to necessary principles and according to contingent ones, according to resolution into the principles of truth and according to the principles that produce and compose a thing into existence; for the limitation of a light cannot comprehend all these, since they ground opposed differences and modes of proceeding.

I SAY SECOND: Logic is essentially and simply speculative by the force of its principles, although it assumes a certain practical mode insofar as it provides rules and direction for speculation itself.

St. Thomas consistently teaches this conclusion. First, he places all the liberal arts under the speculative kind, as in Metaphysics I, lect. 3.⁸ Second, speaking specifically of Logic in Prima Secundae, q. 57, art. 3, ad 3, he teaches that even among speculative objects there is something in the manner of a work, such as the construction of a syllogism or a well-formed sentence, etc. He adds: “And habits of speculation that are ordered to works of reason of this kind are called arts by a certain likeness.” Here he calls not only the act of Logic but also the habit speculative. Yet it is clear in St. Thomas that science is only one habit, as he teaches in Prima Secundae, q. 54, art. 4. Therefore Logic is only speculative. Likewise, in Prima Secundae, q. 47, art. 2, ad 3, he teaches that there is speculative art, but no speculative prudence, because speculative reason makes certain things, such as a syllogism, a proposition, etc. And in q. 51, art. 2, ad 3, he says “that among speculative things one rational science is dialectic and another is demonstrative science, which demonstrates the truth.”

Scotus teaches the same opinion,⁹ as does his entire school in common, although some think that they differ somewhat from the Thomists in their basis; but this is false, for in this latter passage Scotus proceeds from the same basis as St. Thomas, namely, that the work directed by Logic is speculation itself.

Nor can one reply that St. Thomas is speaking of the speculative in a qualified sense, because he says that speculative reason makes something in the manner of a certain work, whereas what is speculative while doing something seems speculative in a qualified sense.

But this will not stand, because in these passages the holy Doctor inquires whether prudence is speculative essentially and simply, not in a qualified sense. For he is inquiring about the very kind of cognition in which the habit of prudence itself is placed; therefore it would be incongruous for him to resolve the question by appeal to the speculative in a qualified sense. He would also be acting altogether foolishly if, when expressly inquiring in what kind of cognition prudence, a liberal art, or Dialectic is placed, he omitted the kind simply speaking and said that it belongs to the speculative kind in a qualified sense; for then he would not explain absolutely and simply what kind it belongs to. When St. Thomas simply affirms that something is such-and-such without any further restriction or explanation, he is not speaking in a diminished or qualified sense, but formally and simply; otherwise we would have nothing certain in St. Thomas’s teaching, especially since the argument was proceeding on this point. The point is pressed further: if it is said to be speculative in a qualified sense, this is chiefly because it acts; but the account of operation as such does not diminish the operation itself, because speculation itself is, in itself, a certain operation, as has already been noted.

The basis of this conclusion can be taken a posteriori and a priori. A POSTERIORI, first, I draw the inference made by the Philosopher in Metaphysics I, lect. 3, as cited by St. Thomas:¹⁰ No science in which knowing itself is sought for its own sake is practical; but one who philosophizes in order to flee ignorance philosophizes solely for the sake of knowing and tends toward knowing for its own sake; therefore such a person is not practical but speculative. This is the inference made by the Philosopher, and precisely the same inference applies to Logic: Logic seeks knowing for its own sake; therefore it is speculative.

The antecedent is proved: Logic intends only to flee ignorance; for it was invented for this purpose, so that reason might not proceed ignorantly or erroneously, but know rightly. Therefore it intends only to know and cognize; for fleeing ignorance and knowing are the same. Therefore, if Logic seeks cognition itself in order to flee ignorance, and to purify knowing itself of error and of the mode of not-knowing, it seeks cognition for the sake of knowing; therefore it is not practical.

This is confirmed because, if Logic directs speculations, then it is the speculative power that is perfected by artificial Logic. Therefore artificial Logic cannot be practical, since it perfects the speculative power; otherwise practical reason would direct speculative reason, and the practical power would be perfected before the speculative power was rectified. That is incompatible, since the practical is posterior to the speculative once it has been rectified, and derives from it, not the reverse.

The A PRIORI basis is taken both from the principles by which Logic proceeds and from the matter about which it is concerned. From the side of the principles: the principles of Logic are entirely speculative, and there is no practical principle even in the construction of syllogisms themselves; therefore Logic itself is not practical.

The consequent is evident. The antecedent is proved as follows. The principles used in constructing syllogisms are these two: “Whatever things are the same as one third thing,” and “Whatever is said of some universal is said of everything contained under it.” These principles are entirely speculative, for they can serve many speculative sciences in proving other truths, and thus attain truth itself as such. The same can be observed in the other principles by which Logic proceeds concerning the nature of genus and universal, the account of opposition, the mode of definition and division, and similar matters. These principles are so speculative that other speculative sciences also use them, as St. Thomas noted in Posterior Analytics I, lect. 20,¹¹ and we often use these principles in other speculative sciences. If, then, Logic has principles that serve speculative conclusions, those principles themselves are speculative; therefore it has no practical principles, since it cannot have practical and speculative principles at once, as was said.

The same is proved proportionately from the side of the matter about which Logic is concerned, because the ordering of Logic directly and in itself concerns the very objects that are known and ordered; from this ordering the formal concepts themselves are directed, insofar as they concern objects ordered in this way. Therefore its matter is not anything practicable.

The consequent is clear, because an object under the state of being known and of second intention is not practicable or operable by any real operation.¹² But if there were any matter practicable and operable by the intellect in reality, it would be the concepts themselves, insofar as they are to be elicited and brought about. Therefore, if the direction of Logic concerns the very objects known, as they are known, it does not concern what is operable as operable.

The antecedent is clear, because the principles by which Logic reasons in themselves and directly regard objects known under the state of being known and of second intention, as when it says: “Whatever things are the same as one third thing are the same as one another”; “Whatever is said of some universal is said of what is contained under it.” The same is true of the rules of amplification and restriction, supposition, etc. In the very coordination of the categories and distinction of the predicables, all these matters regard and concern objects insofar as they are known. Therefore, they do not regard anything operable as operable, since what is operable is what can be attained by a real operation so as to exist in execution, not what is attained extrinsically as something known. For, as we said above, simply because the objects are ordered and presented as such, there is no need to do anything to the concepts themselves so that they may tend toward such objects in some artificial mode, because by their natural representation and likeness they tend toward their objects. Therefore the whole logical art concerns the objects themselves as known, not the very tendency and representation of the concepts, which is natural and can be artificial only objectively, because it is ordered to objects arranged by art.

From these points it follows that an act of intellect is not praxis merely because it is precisely an act of intellect, but because it is speculation and tends toward truth, where it comes to rest. But what comes to rest in truth is contemplative. Hence only external action—that is, action found outside cognition, insofar as it comes to rest precisely in truth—belongs to the practical or active intellect, as St. Thomas teaches in Secunda Secundae, q. 179, art. 2. Acts of the intellect, insofar as they take on moral character and are subject to the movement of free will, can be regulated by the practical rules of prudence, like the acts of the other virtues, because in this way they are in some sense external acts with respect to cognition of the truth, that is, outside it.

THE ARGUMENTS ARE ANSWERED.

First, an argument is made from certain authorities of St. Thomas, by which he seems to attribute to Logic the character of the practical and not the speculative. For in Metaphysics I, lect. 1¹³ and 3,¹⁴ and in opusc. 70, q. 5, art. 1, ad 2,¹⁵ he says that Logic is not contained under speculative Philosophy as a principal part, but as something referred back to it, because the things it treats are not sought for their own sake. Therefore it is not speculative essentially, but only in a qualified and derivative way. In the same place, in the reply to the third objection,¹⁶ he adds that other sciences are called arts when they have not cognition alone but also a work. Therefore, since Logic is both a science and an art, it has not cognition alone but also a work, and consequently has some work distinct from cognition. Again, in Metaphysics VI, lect. 1,¹⁷ and XI, lect. 7,¹⁸ he counts only three kinds of speculative science, following the Philosopher: Physics, Mathematics, and Metaphysics. Logic belongs to none of these, as is evident in itself; therefore it is not in the speculative kind. Finally, that it is not incompatible for a science to be at once practical and speculative is clear from St. Thomas, who attributes both to Medicine in opusc. 70, q. 5, art. 1, ad 4,¹⁹ and Prima Pars, q. 1, art. 4.

The reply to the first passage is that it proves only that Logic is not the most principal among the speculative sciences, but is lower and ministerial, because the things Logic treats serve the other sciences by providing the mode and form of knowing, not as an object in which inquiry ultimately comes to rest. Yet this does not remove its essential speculative character, both because of its mode of proceeding from the speculative principles it uses and because the very things it treats are ordered to other sciences in such a way that they are ordered not to operation but to the speculation of the other sciences, since they provide instruments for speculating.

Regarding the second passage, sciences that are arts are said to have not only cognition but also some work—not a work distinct from speculation itself, but one that orders and directs speculation itself, and thus regards speculation itself in the manner of a work, insofar as it can be regulated and directed by certain rules. Therefore, as we said above, Logic has a certain practical mode; but because all this direction is ordered to speculation and to rectifying the work of speculation, it remains simply speculative.

Regarding the third passage, the reply is as to the first: Logic is contained under speculative Philosophy derivatively, that is, less principally, because the things it treats are less principal, being instruments of speculation.

To the last point, the reply is that St. Thomas expressly places Medicine under practical science according to its end, that is, according to its object, because Medicine as a whole is ordered to operation. It is called theoretical in a qualified sense insofar as some part of Medicine borrows something from Philosophy rather than proceeding from its own principles, as a surgeon borrows from Geometry, or because some part of Medicine is ordered less immediately to operation. Theology, however, is at once practical and speculative because it is a science of a higher order, insofar as it participates in its principles in what belongs to the light of God.

Second, it is argued: Logic regards operations as practically subject to direction; therefore it is practical.

The antecedent is proved because Logic hands down rules and precepts by which the works of reason are ordered so that they may not err in speculation; and if it speculates about anything, it does so in order to direct, not to speculate. Therefore it regards operations as practically subject to direction concerning the mode of speculating, as when it teaches how to construct a syllogism in Barbara according to a certain quantity and quality and other definite, determinate rules by which a syllogism can be regulated.

This is confirmed because Logic directs not only speculative syllogisms but also practical ones. For an incontinent person is said to syllogize badly because he syllogizes with four terms, as the Philosopher says in Ethics VII, lect. 3, as cited by St. Thomas.²⁰ Therefore, just as Logic is speculative because it directs speculations, so it will be practical because it directs practical syllogisms.

The reply: The antecedent is denied. To the proof, it is said that the operations of the intellect can be directed and regulated by a regulation and art that pertains to the known object as known, not by a regulation and art that pertains to the act itself as operable, or to its being elicited in an artistic or moral mode. Rather, the intellect proceeds in a resolutive mode, by natural representation and tendency, toward objects ordered and intended in this way. Hence such direction is in no way practical, for the reasons given. Thus, when it is said, “It speculates in order to direct,” a distinction is made: if the direction pertains to the known object and is ordered only to dispelling ignorance, this is granted, but such direction is speculative; if the direction pertains to the work and is ordered to the thing’s existence or to eliciting it, this is denied. Thus the precepts and rules for constructing syllogisms and the other logical instruments introduce no form into matter in reality, but merely concern known objects according to speculative principles, as was said.

In reply to the confirmation, it is said that in a practical syllogism, although the immediate conclusion is not an operation but reasoning or cognition, the ultimate conclusion is nevertheless an operation, as St. Thomas teaches at length in De Motu Animalium, lect. 5,²¹ and De Veritate, q. 22, art. 15, ad 2.²² Hence this syllogism infers its conclusion not only under the aspect of what is true and known, but also regards the aspect of the good through counsel and judgment. Therefore, its arrangement insofar as it is a practical syllogism—that is, insofar as it is ultimately ordered to operation—belongs not to Logic but to prudence. Prudence nevertheless has some likeness to the arrangement of Logic, because just as one who argues in four terms commits a speculative paralogism, so the imprudent and incontinent person is deceived in practice because he does not rightly arrange the dictate of universal and particular judgment. Hence St. Thomas calls this arrangement a syllogism by likeness and in a qualified sense, in Sentences II, dist. 24, q. 2, art. 4.²³

Finally, it is argued: Moral science is practical; therefore Logic is too.

The consequent is clear by parity of reasoning: moral science is practical because it gives rules for directing acts of the will; therefore Logic is likewise practical because it gives rules for directing acts of reason. The antecedent is proved both because moral science proceeds by practical principles, such as “Good is to be done, evil is to be avoided,” and does not proceed by resolving but by moving; and because if art is not practical science, no science will be practical. For mechanical arts are arts and not sciences, whereas the liberal arts are sciences, but, in our view, are not practical.

This is confirmed because art belongs to the practical part; for the Philosopher counts it together with prudence in Ethics VI,²⁴ where he assigns art and prudence to contingent matter, and science and wisdom to necessary matter. On this see St. Thomas there, lects. 3²⁵ and 4.²⁶ Hence the other liberal arts, such as Arithmetic, Geometry, and Rhetoric, are not speculative but practical; therefore Logic is too.

The reply is that moral science can be considered in two ways: in one way, as also including prudence; in another, as excluding it and concerning itself only with cognition of the virtues by speculation. In the first way it has the character of the practical on the part of prudence, which it includes, and it uses the practical principle “Good is to be done” in a practical mode. There is then a dissimilarity between it and Logic, because prudence directs the works of the will by choice and command, since the works of the will, being free and not naturally tending toward an object, are in themselves capable of real direction and moral motion. Logic, however, as was said, concerns known objects by means of speculative principles and proceeds only by resolutive motion; it does not introduce any real ordering into a concept, since the concept tends toward its object by a natural, not artificial, likeness. If moral science excludes prudence and treats only the subject matter of the virtues by defining, dividing, etc., it is speculative, as occurs in Theology in the Prima Secundae. Nor does it use practical principles or a practical mode—that is, principles that move and incline affectively—but strictly speculative ones, insofar as they cognize the nature of the virtues and of prudence under the aspect of truth, as may be seen in the Ethics and throughout the Prima Secundae. Thus someone may well be an eminent moral philosopher and theologian, yet an imprudent sinner.

Nor is it incongruous that there be no practical science if science is truly and properly science, because science proceeds by resolving and defining, whereas the practical proceeds by moving and composing.

In reply to the confirmation, St. Thomas says in Secunda Secundae, q. 47, art. 2, ad 3, that the Philosopher does not place every art in the same part of the soul as prudence; rather, some art is placed in the speculative part, such as the art that constructs a syllogism. For it suffices for an art that it proceed by certain and determinate means to order something, whether its matter is speculation or something operable. The scientific liberal arts, such as Arithmetic and Geometry, are placed among the speculative sciences by St. Thomas in Metaphysics II, lect. 2,²⁷ and in the other places cited above, since they proceed purely by speculation and by demonstrating truth concerning numbers and magnitudes. Grammar and Rhetoric, however, do not seem to be sciences, nor do they treat the quiddities of objects and necessary connections, but rather modes of speaking and elegance; nor do they proceed by defining and resolving anything into its principles.

It is not enough for a science to be practical that it have the power to produce its acts in particular cases, for then every science would be practical, since every science produces acts in particular cases. Rather, one must see whether such acts concern the truth of a thing by contemplating it and known objects as known, or as operable, and whether they proceed from speculative or practical principles, as was said.

Authors speak variously and obscurely about this distinction between logic as teaching and logic as being used. Logic is called teaching insofar as it teaches scientifically the rules for directing the intellect; it is called being used insofar as it puts those rules into execution in this or that subject matter. This division of logic into being used and teaching was adopted because, just as the things that direct practical activities both hand down rules and have a use, so logic, which directs speculative activities, has these two.

AND THE REASON FOR THE CONTROVERSY is reduced to two points. The first concerns the matter: whether use and teaching in logic deal with the same matter, whether demonstrative or opinionative, or only with topical matter. The second concerns the form: whether the teaching and use of logic belong to the same habit and formal principle.¹

To clarify this obscurity, we need note just one thing from St. Thomas’s teaching: A THREEFOLD USE OF LOGIC can be distinguished. The first is its provision to the other sciences of a way to proceed artfully by syllogistic form. For it belongs to logic to provide the other sciences with a way to proceed so that they do not err, and to direct the works of reason by furnishing instruments of speculation, as St. Thomas teaches from the Philosopher in Metaphysics II, final lecture,² Opusculum 70, q. 5, a. 1, ad 2,³ and Posterior Analytics I, lecture 1,⁴ and often elsewhere.

The second use belongs to logic as teaching, when it provides other sciences not only with syllogistic form but also with principles for deriving certain proofs, just as other sciences too are assisted by others through taking up their principles, especially from metaphysics. St. Thomas teaches that this use belongs to logic in Opusculum 70, q. 6, a. 1,⁵ where he says that sometimes we use logic as teaching in the other sciences because it provides them with certain principles for proving, as when we prove something in the other sciences from the notions of genus, species, or opposition. In Posterior Analytics I, lecture 20,⁶ he gives an example: “We prove,” he says, “that love and hatred belong to the concupiscible power because contraries concern the same thing; this proof is taken from a logical principle, namely, the nature of contrariety.”

The third use of logic is its most proper one: it provides a way of disputing probabilistically in other sciences or subject matters without proceeding demonstratively and resolutively all the way to first principles. In this case logic is properly called logic being used, as distinguished from demonstrating and teaching, because the demonstrator does not merely use reasoning and stop there, but reaches first principles by resolution; these are not proved by reasoning but are its endpoint. Logic being used does reason, but without demonstrating: it uses reasoning and stops there without reaching the endpoint of reasoning, which is resolution to first principles. This belongs to the disputative or tentative procedure, in which one proceeds by inquiry rather than resolution. It is therefore called a probable procedure, because it does not reach the principles with the certainty of a final resolution. This is the act of logic being used,⁷ and St. Thomas explains it in Opusculum 70, q. 6, a. 1,⁸ saying that logic being used is that which uses reasoning but not its endpoint, which terminates in self-evident principles, where the use of discursive reason ceases.

With these points established, it is certain that logic being used, when “use” is taken in the first or third sense (for the second belongs to logic as teaching, since furnishing its principles to others so that they may demonstrate pertains to the exercise of teaching), is not formally called a science. In the third sense, this is because it proceeds only probabilistically or disputatively, not resolutively. In the first sense, it is because that use of logic is not demonstration, which alone confers the name of science, but an application and concurrence that arranges syllogistic form, whether in demonstrative or topical matter; hence it is not a determinate use of science and demonstration. As for the difficulties raised, however—

I SAY FIRST: Logic being used, when use is taken in the first sense, must direct not only the topical part but also the demonstrative part—and indeed especially the latter.

We use the word “direct,” although some in this sense call it not logic being used but logic directing, so that we may avoid a dispute over the name. For the use of logic in this respect is direction, just as the higher sciences and architectonic arts have as their proper act or use the directing of lower ones.

This conclusion is taught by St. Thomas, first, in Posterior Analytics I, lecture 1,⁹ where he says that not only the other works of reason, but especially its judging or demonstrative part, is directed by logic. Second, he teaches that logic supplies instruments of speculation to all sciences—which certainly proceed demonstratively—in Opusculum 70, q. 5, a. 1, ad 2,¹⁰ and in Metaphysics II, final lecture,¹¹ he teaches how logic provides every science with a method of knowing. Therefore the use of logic must not be restricted here to the topical part alone, but extends also to the demonstrative part.

THE REASON IS clear: demonstration requires the structure of a syllogism and the goodness of a consequence, regulated according to logical rules and principles, no less than other probable syllogisms do. Therefore the arrangement and artful form in demonstrations derives from logic. It depends on logic’s principles and rules both with respect to form, which is regulated by “said of every” and “said of none” and by other principles that arrange the syllogism, and with respect to matter, because demonstration must use necessary and per se propositions, which logic especially considers in resolutive reasoning of the Posterior Analytics.

It is no objection that, even when rightly arranged, these demonstrations proceed effectively from the particular sciences that arrange the syllogism, while they depend on logic only for direction. I say this is no objection because we are not now determining that logic influences demonstrations in the other sciences by effectively eliciting them; it is enough that it influences them by directing them, just as prudence influences the virtues not by eliciting their acts but by commanding them. Or, if logic does influence them effectively, its influence is not that of a principal cause demonstrating, but of an assisting and furnishing cause. Virtues elicit a moral act regulated by prudence, whether that mode of regulation in the acts of the virtues is effectively caused by prudence through a real impression in the moral virtues or only by direction; this does not pertain to the present question, but to the question whether the command of a superior power or virtue over the lower powers it moves occurs through an effective impression. Whatever the answer, it is clear that with respect to an opinionative and probable syllogism as well, logic influences its syllogistic arrangement no more effectively and elicitingly than it does a demonstrative syllogism, but only by direction. We say that logic has this same direction or use in a demonstrative syllogism.

I SAY SECOND: Logic being used, taken in the third sense, deals only with the topical and sophistical part, that is, with a procedure that is not resolutive but probable, probative, and disputative. If such use takes place in other sciences from the principles of those sciences, disputing from them without resolution, that use belongs to logic only as directing. But if such a non-resolutive disputation proceeds from logic’s own principles, it will belong to logic not only as directing but also as eliciting, like a secondary and imperfect act.

St. Thomas intends this conclusion in Metaphysics IV, lecture 4,¹² when he says that “logic, insofar as it is teaching, considers these logical intentions, establishing a method by which one can proceed probabilistically through them in the several sciences, and thus it is a science. But it is being used insofar as it uses this method in order to conclude something probabilistically in the several sciences, and thus departs from the method of knowing.” St. Thomas teaches this more explicitly in the cited Opusculum 70, q. 6, a. 1,¹³ where he says that “a rational procedure is sometimes named from the endpoint at which it stops while proceeding. The ultimate endpoint to which reason’s inquiry must lead is understanding of the principles, into which we judge by resolving; when this happens, it is called demonstration. But when reason’s inquiry does not reach the ultimate endpoint, but stops in the inquiry itself—when, that is, the inquirer still has a path open either way—then rational procedure is distinguished from demonstrative procedure. One can proceed rationally in this way in any science, so that a path to necessary conclusions is prepared from probable things. This is another way in which logic is used in the other sciences, not as teaching but as being used.” Thus St. Thomas.

Taking logic being used in this sense, it is clear that it does not pertain to the demonstrative part but to the topical part, because such use is not demonstration: it is not resolution with full determination to certain and evident principles, but proceeds only by inquiry and disputation toward either alternative. If it does so by providing principles proper to that reasoning and disputation, logic elicits the whole procedure, because it provides not only the method of disputing but also the matter or principles. Whatever a habit derives from its own principles and object belongs to that habit elicitingly, whether the derivation is resolutive or only disputative. But if the procedure or disputation is formed from principles of other sciences or habits, then logic provides only the method of disputing—that is, it provides direction, not the eliciting of the act in its substance.

I SAY FINALLY: The habit of logic as teaching and as being used is the same, whether it directs or elicits, disputes probabilistically or proceeds demonstratively; and the specific formal rationale of each is the same.

Not everyone agrees with this conclusion. Some take one extreme and say not only that logic being used and logic as teaching are the same habit, but that the very same act both uses and teaches; this is Martínez’s view here, q. 2. Others take the opposite extreme and posit not only distinct acts but distinct habits as well, because they say that logic as teaching is speculative and logic being used practical, as Vázquez does in part I, disp. 8, ch. 5, no. 19; or because they say the teaching habit is scientific, while the habit of use is opinionative, as some cited by the Coimbra commentators, q. 4, proem, a. 2. Others say that logic as teaching and being used is the same habit in the matter and object proper to logic, but that in other sciences the user is not the habit of logic; rather, it is the habit of those other sciences itself that produces its inferences in an orderly way. So Master Cabero, disp. 2, proem, doubt 2. Father Merinero here, q. 2, section 2, does not in substance depart from him: he distinguishes the habit of logic being used elicitingly from the habit of logic as teaching; when it deals with the matter of other sciences, he says, that eliciting belongs to the habits of those sciences.

Nevertheless, the proposed conclusion, stated absolutely and without so many distinctions, is more common among authors, and especially among Thomists. On this point one should consult Flandricus, Metaphysics II, q. 5, a. 2, ad 2; Master Araujo there, q. 3, a. 2; Master Soto, Sánchez, Masius, and the Carmelite Course, disp. 1 (proem), q. 4, § 2.

THE REASON IS that the other sciences do not have within themselves principles that order their inferences; rather, they borrow them from logic, which hands them down and explains them. Therefore they elicit ordered consequences only through the power of logic, or through the light communicated to them at least by direction and by presentation of the object. Thus St. Thomas continually teaches, especially in Opusculum 70, that logic furnishes the other sciences with instruments of speculation. Logic itself teaches the method of speculating and uses it through the same habit, because in any subject matter it uses and applies the same principles by which it hands down its teaching to form consequences; it requires neither a distinct judgment nor any special difficulty to be overcome. Therefore it does not require a distinct habit, but only an extension or application of the same habit.

The antecedent is proved. It is plainly clear that the procedure comes from the same principles: if it applied other principles that did not belong to logic as teaching, then it would no longer be merely logic being used, but logic as teaching, since it would be handing down other principles; they would be distinct sciences proceeding from distinct principles, and so they would be called two teaching sciences, not one teaching and one being used. Therefore the use and direction of logic must necessarily agree in the principles of its teaching.

That it does not need a distinct facility and habit for the sake of application is clear from what was said in the preceding article: the entire difficulty of logic’s direction or ordering consists in knowing the second intentions themselves insofar as they are grounded in the first. Once this is known, the application itself presents no special difficulty, because application itself is made to things known through acts that, by their natural representation and tendency, regard objects, not through a moral or voluntary motion or an artful deduction. The whole art and ordering belongs to the ordered object’s side, through the second intentions, as was said. Therefore the difficulty is not in directing acts so that they may be elicited, but in knowing the objects to which the second intentions are applied.

Likewise, on the side of the objects themselves, once the rules and precepts of logic, which are taught demonstratively by its teaching part, are known, there is no difficulty in applying and using them in this or that subject matter; it requires only the addition of the subject matter, to which the rules apply and extend without any new difficulty to be overcome on their part. It is like someone who has the art of music or plays the lyre: from the same precepts of the art, that person can apply the fingers to any instrument offered. If the person cannot move the fingers, or cannot move them so readily, no new art is needed to overcome this difficulty, but bodily practice or something else to remove the impediment just mentioned. Thus the person who moves the fingers more readily does not acquire a new art but removes an impediment to its exercise. So when the intellect is exercised in syllogizing about different subject matters or sciences, it does not acquire a new art or habit distinct from the teaching of logic itself, but a more ready use of it.

OBJECTIONS ARE ANSWERED.

First it is argued to prove that logic being used is found only in the topical part, and not in the demonstrative part. For St. Thomas seems expressly to say in Metaphysics IV, lecture 4,¹⁴ that in the part of logic called demonstrative only teaching belongs to logic, while use belongs to physics and the other particular sciences; but the tentative and sophistical parts of logic have both teaching and use. Therefore, according to St. Thomas, the demonstrative part is not logic being used.

If it is said that St. Thomas is speaking of use in which one proceeds probabilistically from logical principles in the other sciences—which certainly belongs to the demonstrative part, as he teaches in Posterior Analytics I, lecture 20,¹⁵—and not of use in which logic provides the very syllogistic form and artful method to the other sciences, which also belongs to the demonstrative part.

The contrary is the case: the other sciences elicit their demonstrations through their own power, not through the power of logic, and produce them in an orderly way, otherwise they would not be demonstrations. But that second intention of syllogistic form, since it is something of reason, is not made; it results from the very cognition that demonstrates. Therefore neither the eliciting of a demonstration nor that method or form of reason requires logic’s eliciting activity and use.

THE REPLY is the solution given during the argument. And to the reply it is said that a demonstration proceeding from a particular science receives from that science the character of a special demonstration, from the special character of that science. But it receives the character of an ordered and artful procedure through logic’s direction, not through the particular science’s own power, insofar as logic influences the other sciences, whether through an effective influence impressing some reality in the acts or through direction from the side of the object, which it presents as ordered, as we now presuppose. Thus the particular science does both: it considers the special truth through its own power, and orders the object through the power of logic’s direction. Although that mode or syllogistic form is a being of reason resulting from cognition, it does not result from the cognition of that science insofar as it is a particular science, but from logic’s directive cognition, which directs all sciences universally and affects that particular science.

Second it is argued: The act of logic being used is neither scientific nor demonstrative; therefore it does not proceed from the habit of logic.

The consequent is clear: the habit of logic is evident and certain, since it is a science; therefore it cannot elicit an opinionative act, which is uncertain and nonevident. So the act proceeds from another habit, and thus the habit of logic as teaching differs from that of logic being used. Again, logic as teaching proceeds in a resolutive and speculative manner, while logic being used proceeds applicatively and compositionally; therefore they are different habits.

THE REPLY: The consequent is distinguished. That a probable act does not proceed from the habit of logic as its primary and per se act is granted; that it does not proceed from it secondarily and indirectly, or even by direction, is denied.

It is no problem for an evident and certain habit to elicit a probable act or even to direct one toward it as a secondary and imperfect act. There is less difficulty in the case of direction, because logic teaches by certain scientific rules how an opinionative assent should be directed. Consequently, although something is opinionative on the side of the matter, it is scientific on the side of the method of direction and the rules by which it proceeds. That the habit of logic itself elicits an opinionative act and does not merely direct it is more difficult, but can nevertheless be explained from what was said. In a scientific habit, the primary act, which proceeds perfectly and resolutely by deriving conclusions all the way to first principles, is always certain and evident. Yet there is no contradiction in its sometimes forming from the same principles an imperfect procedure that is not fully resolutive, but proceeds only disputatively and tentatively; such a procedure is probable. A generator produces not only a perfect effect perfectly like itself, for example, a human being or a horse, but sometimes also an imperfect one, such as an embryo or even a monster or something degenerating from its perfection, although the power is perfect; this occurs because of some impediment, the incapacity of the matter, or the agent’s failure to apply itself. Likewise, logical science can use reasoning and scientific principles without fully resolving, but by inquiry and trial; this is an imperfect act. St. Thomas also teaches in Summa theologiae II–II, q. 1, a. 4, that the habit of faith knows its own credibility evidently, and an opinionative habit knows probability, while each apprehends its object obscurely, namely, the thing believed or opined. Thus evidence and lack of evidence do not concern the same thing: one concerns the thing believed, the other its credibility.

Although these seem to be several acts specifically distinct, they are specifically distinct as it were materially, not formally or on the side of the formal rationale. A virtue can have diverse inadequate acts specifically distinct as it were materially and partially, as religion has prayer, devotion, and so forth, which are diverse inadequate and partial acts.

As confirmation, it is said that logic being used does not proceed compositionally on the side of the rules and principles it uses, since these are the very principles of logic as teaching; it only applies those rules to determinate subject matter so that speculation itself may be rightly ordered. The fact that the very method of speculation is applied to diverse subject matters does not give it the character of something practical, as we said above, because what is applied is speculation.

Finally it is argued: Prudence is a virtue and habit distinct from synesis and eubulia, as St. Thomas teaches in Summa theologiae II–II, q. 51, a. 2; yet they are distinguished only because these two judge and deliberate well, while prudence commands and carries out. Therefore, similarly in logic, the teaching and judging habit is distinct from the operating and using habit.

It is confirmed because repeated acts of logic being used generate some habit, but not the habit of logic as teaching, since they are not scientific acts and thus neither generate nor increase science; therefore they generate another habit, distinct from the teaching habit.

THE REPLY: The consequent is denied. The difference is that in prudence there is a distinct difficulty in commanding and applying the will to action, as compared with judging and deliberating; in logic there is not. The basis for this is taken from St. Thomas’s teaching in Summa theologiae II–II, q. 47, a. 8: the perfection of art consists in judging, not commanding, whereas the perfection of prudence is the reverse. Hence a craftsman who willingly errs in his craft is considered better than one who errs through ignorance; conversely, the one who willingly errs is more imprudent. This is especially true of the art of logic, whose matter is the acts of reason themselves: the entire difficulty for the intellect lies in judging or ordering some truth. Whatever remains, namely, directing other acts from this truth once known, presents no special difficulty, because the intellect naturally tends toward objects once they have been presented. Thus the entire art and ordering belongs to the side of objects, which are attained by cognition naturally tending toward them. In moral matters, however, after the good has been judged and known, the chief difficulty remains in applying the will because of its freedom, indifference, or resistance to the regulated good. Hence a distinct habit is required, in which prudence is perfected.

To the confirmation the reply is that acts of logic being used generate a certain facility by way of disposition and readiness in applying subject matter, not by way of a new art or habit. For a habit is newly generated or increased not by just any acts, but by those that per se attain the habit’s own specific rationale and formal motive, not those that follow secondarily or are merely disposed toward it. A habit is newly generated or increased only according to its substantial and formal rationale; other formalities are accessory.

An example is found in St. Thomas, Summa theologiae II–II, q. 144, a. 1, ad 5, where he says that repeated acts of modesty do not generate a habit distinct from temperance, because modesty is not a habit of perfect virtue but a disposition toward generating temperance. Therefore not all repeated acts, even imperfect and secondary ones, generate a new perfect habit such as science; they generate something imperfect in the genus of habit, which is as it were a disposition or a certain readiness in the very exercise of the art. The distinction between disposition or readiness and habit is better understood in things pertaining to the intellect, because sometimes we find a habit without ease in exercising it—for example, a habit of science that does not yet have ordered and ready species for all the other conclusions of the science. Conversely, we find ease in exercising without a habit in someone who has ordered species and frequent practice of all the conclusions, but who lost the habit through an error in some principle—for example, through an error in faith, someone lost the principles of true theology and consequently the habit of theology itself, but not the ordered species of its conclusions.