Cursus Philosophicus Thomisticus, Prima Pars Artis Logicae
John of St. Thomas (1589–1644)
First published 1930
Prima pars artis Logicae (formal logic) of the Cursus Philosophicus Thomisticus of John of St. Thomas (Joannes a Sancto Thoma), from the Reiser edition (Marietti, Turin, 1930), Reiser tomus I, pars prima.
Praefatio I: Preface
Praeludium I: IN WHICH THE EXERCISE AND PRACTICE OF DIALECTICAL DISPUTATION ARE PROPOSED
Praeludium II: DIVISION, ORDER, AND NECESSITY OF THE ART OF LOGIC
Liber I: ON THE MATTERS PERTAINING TO THE FIRST OPERATION OF THE INTELLECT
Caput I: DEFINITION OF THE TERM
Caput II: DEFINITION AND DIVISION OF THE SIGN
Caput III: ON CERTAIN DIVISIONS OF TERMS
Caput IV: ON OTHER DIVISIONS OF TERMS
Caput V: ON THE NAME
Caput VI: ON THE VERB
Liber II: ON THE MATTERS PERTAINING TO THE SECOND OPERATION OF THE INTELLECT
Caput I: ON EXPRESSION IN GENERAL AND ITS DIVISION
Caput II: ON THE MODE OF KNOWING
Caput III: ON DEFINITION
Caput IV: ON DIVISION
Caput V: ON ARGUMENTATION
Caput VI: ON THE PROPOSITION OR ENUNCIATION
Caput VII: ON THE DIVISIONS OF THE PROPOSITION
Caput VIII: ON THE MATTER OF PROPOSITIONS
Caput IX: ON THE PROPERTIES OF THE PROPOSITION AND THE ORDER IN WHICH THEY ARE TO BE TREATED
Caput X: ON SUPPOSITION
Caput XI: ON THE DIVISIONS OF SUPPOSITION
Caput XII: RULES OF SUPPOSITION
Caput XIII: ON RELATIVES
Caput XIV: ON AMPLIFICATION, RESTRICTION, AND ALIENATION
Caput XV: ON APPELLATION
Caput XVI: ON OPPOSITION
Caput XVII: ON THE CONDITIONS REQUIRED FOR THE SPECIES OF OPPOSED PROPOSITIONS AND THE RULES FOR RECOGNIZING THE SPECIAL OPPOSITIONS THEMSELVES
Caput XVIII: ON THE EQUIVALENCE OF PROPOSITIONS
Caput XIX: ON THE CONVERSION OF PROPOSITIONS
Caput XX: ON MODALS
Caput XXI: ON THE QUANTITY, QUALITY, OPPOSITION, AND EQUIVALENCE OF MODALS
Rotuli I: TABLES OF COMPOUND MODALS
Rotuli II: TABLES OF DIVIDED MODAL PROPOSITIONS WHOSE DICTUM CONCERNS A COMMON TERM
Caput XXII: ON THE REDUCTION OF MODALS TO THEIR DE INESSE PROPOSITIONS
Caput XXIII: ON HYPOTHETICAL PROPOSITIONS
Caput XXIV: ON EXPONIBLES
Liber III: ON THE THIRD OPERATION OF THE INTELLECT
Caput I: ON CONSEQUENCE AND ITS DIVISION
Caput II: ON INDUCTION
Caput III: ON THE ORDER AND MODE OF RESOLVING TERMS BY ASCENT AND DESCENT
Caput IV: ON THE SYLLOGISM AND ITS MATTER AND FORM
Caput V: ON THE DIVISION OF THE SYLLOGISM ACCORDING TO MATTER AND FORM
Caput VI: ALL THREE FIGURES AND MODES OF SYLLOGISMS ARE EXPLAINED
Caput VII: ON THE REDUCTION OF IMPERFECT SYLLOGISMS TO PERFECT ONES
Caput VIII: ON THE EXPOSITORY SYLLOGISM
Caput IX: ON THE MODE OF FINDING THE MIDDLE TERM
Caput X: ON THE PRINCIPLES ON WHICH THE WHOLE ART OF SYLLOGIZING RESTS
Caput XI: ON THE PRINCIPLES ON WHICH THE GOODNESS OF CONSEQUENCE RESTS UNIVERSALLY
Caput XII: ON THE PRINCIPLES OF THE DEFECTS OF A BAD CONSEQUENCE
Caput XIII: ON PARTICULAR DEFECTS
Circa I: CONCERNING THE SYLLOGISM.
Defectus I: COMMON DEFECTS.
Caput XIV: ON FALLACIES
Liber IV: THE FOLLOWING QUESTIONS ARE TO BE DISPUTED TO ILLUSTRATE CERTAIN DIFFICULTIES OF THIS TEXT
Quaestio I: ON THE TERM
Articulus I: WHETHER DIALECTIC BEGINS WITH THE TERM IN THE RIGHT ORDER OF DOCTRINE
Articulus II: WHETHER THE DEFINITION OF THE ENUNCIATIVE TERM IS GOOD, AND IN WHAT ITS FORMALITY CONSISTS
Articulus III: WHETHER THE DEFINITION OF THE SYLLOGISTIC TERM IS GOOD, AND WHAT ITS FORMALITY IS
Articulus IV: WHAT THE DEFINED THING OF A TERM IS, AND FOR WHAT IT SUPPOSITS
Articulus V: WHETHER WORDS SIGNIFY CONCEPTS OR THINGS FIRST
WE ASSUME as certain among all that words signify concepts, both formal and objective, since this is plainly established by the Philosopher in On Interpretation I, ch. 1.1 Experience also plainly attests it. For when we wish to make manifest not only what we conceive but also that we conceive, we do so through the words with which we speak. Let Thomas be consulted, On Interpretation I, lect. 22 and On the Power of God, q. 9, a. 5, where he says, “a word signifies a concept of the intellect, through which it signifies the thing.”3 Here he plainly distinguishes between the formal and objective concept and attributes both to the word. And in Against the Gentiles IV, ch. 11, he says, “the understood intention is a conceived likeness, which external words signify.”
THE DIFFICULTY, then, can concern two things: first, whether words signify concepts and things by the same signification; second, which they signify more principally, things or concepts. The same can be asked about writing in relation to words.
Concerning the first point, some hold that words signify things and concepts by two significations, and they cite Master Soto in support of this view, but without justification: he did not say that a noun signifies things and concepts by two significations, but that “signifying by a noun is taken in two ways,” either as moving a power or as expressing concepts; nevertheless, both functions can belong to one and the same signification.
THEREFORE, I SAY: Words signify things and concepts by one signification.
THE REASON is that they signify both by the same imposition; therefore, they do so by the same signification.
Second, they signify things and concepts neither with equal immediacy nor separately, one apart from the other, but one through the other and as subordinated to the other; therefore, one signification suffices for both.
The consequence is clear: where there are several subordinated things, they are signified by the same signification, just as the noun “human,” for example, signifies not only human nature but also the individuals for which it supposits, by the same signification. The antecedent is established both by Thomas, Summa theologiae I, q. 13, a. 1, and On the Power of God, q. 9, a. 5, where he says that words immediately signify conceptions of the mind and, through them, things.4 He says the same in On Interpretation I, lect. 2.5 And also because if a word signified things and concepts by different significations, so that they were not subordinated to one another, every noun would be equivocal; and it would not be contradictory for one signification to be removed while the other remained, so that it would signify a concept but not a thing, or conversely—which is absurd.
Note, however, that a concept can be signified in two ways. First, as it is in itself a thing in act, in the state of what is signified, and as knowable reflexively through another concept. In this way a concept is signified by a special name imposed for this purpose, such as the word “concept”; for it is signified like other things. In another way, concepts are signified as certain interior signs, or means of conceiving things, from which these exterior signs derive and through which the interior signs are made manifest; thus words signify concepts as exercising this function.
BUT YOU WILL OBJECT: There are two impositions for signifying things and concepts; therefore, there are two significations.
The consequence is evident, and the antecedent is proved as follows: people first wished to communicate their concepts in common; then they devised a means suited to such communication, namely the imposition of words. Therefore, there were two acts and, consequently, two impositions.
It is confirmed because words signify things themselves “as that which” and doctrinally—that is, as what is signified in the teaching of doctrines—whereas concepts are not signified but indicated. Hence words are said to be substituted for concepts, but to signify things.
The argument is answered as insufficient, both because it would prove the same about the signification of things alone: people first wished, as it were, to signify things in common, and then devised a means of signifying them through the imposition of words; and also because willing or intending to do something and then carrying it out by choosing the means through which it is to be done does not produce two effects, since, with respect to the same effect, there must be intention, choice, and execution. Therefore, it does not follow that there were two impositions because they willed it through two acts, by intending and executing.
As to the confirmation, the answer is that all those functions belong to one signification, since the whole is signified according to a certain order. For the same signification of a word has a twofold office: namely, to stand for the things it manifests, and, second, to stand for the concepts that signify those things secretly and inwardly. The whole is accomplished by one signification and one imposition, because this sensible sign is imposed to manifest that interior sign in relation to the things thought of—just as a king’s minister, through the same ministry and office, stands in for the king as principal, in relation to certain things to be governed as an end.
SECOND, YOU WILL OBJECT: A word cannot signify a concept immediately and a thing mediately; therefore, it is false to say that it signifies a thing through a concept. Rather, it must signify the thing immediately, and so by a different signification.
The antecedent is proved: first, a concept is not the thing signified reflexively, since that is done by the word “concept”; nor is it the formal principle of signifying, since that is the imposition; nor is it a condition required on the side of the thing signified, for words signify things not as conceived but as existing in themselves. Second, words do not signify through the concept of the hearer, the speaker, or the imposer; therefore, they signify through no concept. Not through the hearer’s, because the hearer is not the one who declares his own concepts, but the one to whom another’s concept is declared. Not through the speaker’s, because words signify even if there is no speaker—for example, if words are formed in the air or by someone asleep—and, moreover, the speaker’s concept is outside the hearer, so it is not a means for him to know the thing. Not through the imposer’s, because through a word we neither recall the imposer himself nor know what his concept was. Indeed, a word may represent the thing better to me than the imposer himself conceived it; therefore, the imposer’s concept is not the principle of representation.
The antecedent is denied in response. But one must note that signifying one thing through another can be understood in three ways. In one way, through another as a formal principle, but not as a represented thing—as a word is said to signify through imposition, a concept through likeness. Second, through another as a represented thing that is primarily and immediately signified—as “human” is said to signify a human being in general immediately, and Peter, who is a human being in the singular, mediately. Third, through another, not as a thing signified but as a principal signifier, whose substitute and, as it were, instrument the word is, because it participates in the being and signification of the mental word, as St. Thomas says, On Truth, q. 4, a. 1, ad 7.6 In this way a word signifies a concept, because it is put in its place as a substitute, to supply what the concept cannot reach: namely, to make it manifest externally both to itself and to others. Thus a word is like a substitute that represents its principal, which it serves, rather than that toward which it is ordered, namely, the thing signified.
To the first proof, the answer is that words signify concepts not as things directly signified, but as principal signifiers. They also represent things as conceived, not by taking “as conceived” reduplicatively, for the state in which they are known, but specifically and in the exercise of signification, as a condition with which they are represented, since in fact they have been conceived. Sometimes, however, things are signified as they are subject to the intention and state they have in the mind, and the intention itself is, as it were, a represented thing, as with logical intentions such as species, genus, and so on.
To the second proof, it is said that words receive their signification and imposition from the concept of the imposer as from its source, but are substituted for the speaker’s concept as that in whose place they stand; for they are imposed so that they may be substituted by any speaker.7 When words are formed by someone who is not speaking, those words are not speech, but a material sound like speech; hence they do not signify through imposition, but through the custom we have when we hear similar words, since they resemble words that are speech. Hence Thomas says, Summa theologiae I, q. 51, a. 3, ad 4, that a word formed by an angel is not properly a word. And even if these were genuine words and did not signify the speaker’s concept when thus formed, it would not follow that, when they do signify it, they signify concept and thing by different significations, but by the same signification, which has the power to signify both but does not always exercise both functions; for we do not always attend to the speaker’s concepts by discerning them from things. And although the speaker’s concept is outside the hearer, it is present to him in itself through the word, by which it is made sensible.
Regarding the second point of this article—namely, what words signify more principally, things or concepts—the answer is that they signify things more principally, unless perhaps the thing signified is itself a concept or its intention.
THE REASON IS that the concept is ultimately and principally ordered to representing the very thing of which it is an intentional likeness. Therefore, the word, which is only an instrument of the concept in representing and makes the concept itself sensible, will be ordered more principally to representing those same things, since it serves the concept for this very purpose. And although an instrument seems to regard its principal, by which it is moved, more principally than the effect it produces, this is understood in the order of operating and acting. In the order of representing, however, if what is principal is also representative of things and, in order to extend and make that representation manifest to others, substitutes some instrument for itself, the chief signified object in both cases is the thing itself. Hence Thomas says, On the Power of God, q. 9, a. 4,8 that “what is formally signified by a name is that for signifying which it was principally imposed, as the name ‘human’ was imposed to signify a composite of body and rational soul.”
And if you say: A concept or word does not principally signify the things expressed, but its own source of expression, as appears in the Divine Word, which represents the Father, whose likeness it is, more principally than creatures; therefore, an external word, too, will represent its source—that is, the concept—more principally than the thing signified and expressed.
I answer that a concept or word is an expression of its formal principle, which is the impressed species that fecundates the expressing intellect; and this represents the object of which the species is formally the species. Thus, by representing its formal principle, a concept represents its formal object more principally. Creatures, however, are a secondary and material object, and therefore are not represented principally by the Divine Word. Hence it does not follow that an external word represents a concept more principally, since the concept is not the formal object represented, but the principal signifier. Besides, a word is not a natural expression of its source as a concept is, but is imposed and directed to signify what the concept signifies.