Cursus Philosophicus Thomisticus, Secunda Pars Artis Logicae

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.