Universa Philosophia

Aristotle in the first book of On Interpretation, ch. 4, Peter of Spain, book 1, ch. 6, and other Summulists say that a proposition is a sentence signifying truly or falsely. The Conimbricenses, q. 3, art. 2, rightly note that a proposition is better and more profoundly defined by affirmation and negation than by truth and falsity; for a definition is the quiddity of a thing; but truth and falsity are not the quiddity of a proposition, but affirmation and negation, from which truth and falsity arise (as will be clear in disputation 9 on the soul, section 1); therefore a proposition is not to be defined by truth and falsity. And indeed Aristotle in that chapter is wholly occupied with explaining the negation and affirmation of a proposition; but when he defined a proposition in that chapter, he premised the definition as clearer for boys who understand nothing clearly. Second, a definition is not to be given through a disjunction of differences, except to avoid obscurity, but through a common concept; as animal would be badly defined as rational or irrational, but as living¹, sensible; so neither is a proposition thus to be defined. Third, because even in apprehension an incomplex truth is found (as I shall show in that disputation 9), although it is not a proposition.

A proposition is therefore a judicative act of the intellect: the first part is the genus, by which a proposition agrees with simple apprehension; it does not differ from discourse, because it is also judicative; but it differs from apprehension, which is not inclined to either side, but precisely stops in the representation of the object. Judgment is divided into affirmative and negative: the former affirms one thing of another, or says that both terms are the same, as Petrus est homo, which is signified by the verb est; wherefore the verb is called the copula, or union of extremes, because in the mind they are united intentionally, that is, they are not divided but mutually joined. But adjectival verbs are explained by a participle and the substantive verb, as tu scribis, that is, es scribens. The other judgment is negative, by which one term is denied to agree with the other, as Petrus non est lapis, which is called division, because the union of the verb is denied; but things not united are divided; therefore, because the mind denies the copula of the extremes, the terms are divided in the mind; and on the contrary, affirmation is called composition.

A proposition has been defined by me more in the manner of the science of the soul than in the manner of the Summulists; it will be a perfect sentence substituted for a judgment of the mind, or it will be a judicative sentence, or it will be a sentence affirming or denying something; or it will be a sentence signifying truly or falsely. I have already warned in disputation 2 that utterances are substituted for concepts, and that they ought to be explained by comparison with them.

The matter of a proposition is the object of judgment, which, because it is set before the intellect, is customarily called the underlying matter, as is clear from disputation 1 of logic, section 1; as Petrus currit, Petrus et eius cursus are the matter about which the proposition is concerned. This matter is threefold. The first is called necessary, when the predicate cannot fail to agree with the subject, as Petrus est homo, because it implies that Peter is without being a man. The second is remote, because the predicate is so removed from the subject that they cannot be the same, as Petrus est lapis. The third is contingent, because the subject can be with the predicate and also can be without it, as homo currit. The union of the verb is called by some the form of the proposition; but the union is also matter, because it is the object of judgment.

The quality of a proposition is said by some to be affirmation and negation; but its essence is said to be truth or falsity. That this is false is clear, because quality is an accident, but affirmation is not an accident of a proposition, as is clear in §1; therefore it is not quality. Likewise, an accident is not an essence, but truth is as it were an accident of a proposition; therefore it is not an essence. Others, as the Conimbricenses and Fonseca, say that affirmation and negation are the essential quality of a proposition, but truth is an accidental quality. I grasp the matter and approve it; I cannot approve the phrasing, because quality is an accident, but essence is not an accident; moreover, to join quiddity and accidental is to join repugnant terms, as if someone were to say that man has an irrational rationality. Therefore the essence of a proposition is to affirm or deny, but its quality is to be true or false.

Quantity is not found properly in a proposition, but by a trope. For in a body the magnitude and smallness of a thing depend on quantity: if it is extended far, it makes the body large; but if it is contracted, it makes it small. So the quantity of a proposition is that by which a proposition is made great or extended and stretched out to many objects, or by which it is restricted to few. Hence to one asking what is the proposition? it is answered affirmative or negative. Of what sort is it? True or false. How much? Universal or singular. The quantity of a proposition is therefore divided into universal, particular, confused, and singular, as omnis homo currit, aliquis homo currit; this is confused, which others call particular; Hic homo currit. Quantity depends on the subject, and as the subject is supposed, the proposition is called universal or singular.

Some propositions are absolute, some depend on something else, e.g. Petrus est homo is an absolute proposition, because its truth or falsity does not depend on anything else, but only on the absolute identity or distinction of subject and predicate: wherefore a proposition of this kind is called categorical. But I have shown in disputation 1, section 9, that a category is a predication, likewise that a categorematic term is perfectly significative by itself and absolutely; whence I infer against some Summulists that a categorical proposition is not interchangeable with a simple utterance, for a complex proposition can be categorical, as Petrus currit, et Ioannes legit is an absolute proposition and perfectly significative by itself. But let an example of a proposition depending on something else be: si Petrus venerit, loquetur; the subject is joined with the predicate not absolutely, but with dependence on Peter's arrival: nor can it be said absolutely that Petrum locuturum aut non, nor that the proposition is absolutely true or false, unless Peter's arrival is awaited, on which both the speech and the truth of the proposition depend.

This proposition can rightly be called syncategorematic, because the copula of the verb does not signify by itself absolutely, but dependently on a condition. Yet it is better called hypothetical. For hypothesis sounds in Greek what in Latin is supposition or condition: wherefore a complex proposition, or one consisting of two, is not interchangeable with a hypothetical, because this Petrus currit, et Paulus loquitur is not hypothetical, since no hypothesis is established in it; therefore a categorical proposition is a proposition absolute, which judges absolutely about its object. But a hypothetical is a conditional proposition, which judges about its object dependently on some hypothesis or supposition, just as an absolute promise is one which does not depend on a condition, as dabo tibi centum, but a conditioned promise depends on a supposition, as si Navis venerit dabo tibi centum. See this teaching in Toledo, book 1, chapter 19, although Peter of Spain, book 1, chapter 15, says that the hypothetical is one composed of two categoricals, but not well, as I have observed, because it is against the etymology of the name and its manifest account.