Daily Lessons from St. Thomas

Aquinas Day By Day


Aquinas’s topic: logic of judgments:  quantity of categorical propositions

Scripture: “Israel loved Joseph best of all his sons, for he was the child of his old age; and he had made him a coat of many colors.  When his brothers saw that their father loved him best of all his sons, they hated him so much that they would not even greet him.” Genesis 37:3-4

Aquinas’s text:  Expositio libri Peryermenias Bk. 1, lec. 10, n. 13-16

Here Br. Thomas explains the four kinds of quantity that can be found in the subject of a categorical proposition:  universal, particular, singular, and indefinite.  In scholastic logic, these four categories are often reduced to two: universal and particular, by treating singular propositions as universal and judging whether an indefinite proposition is indended as universal or particular.

13] Sometimes something is attributed to a universal by reason of its universal nature; and then this is said to be predicated of it universally, namely, because it belongs to the whole multitude in which it is found. In order to designate this in affirmative predications the term “every [omnis]” was invented; it designates that the predicate is attributed to the universal for all that is contained under the subject. But in negative predications the word “no [nullus]” was invented in order to signify that the predicate is removed from the universal subject for all that is contained under it. Conseqeuntly, saying nullus in Latin is like saying non ullus [not any], and in Greek oudeis [none] is like oude eis [not one], for one cannot find a single one under the universal subject from which the predicate is not removed.

On the other hand, sometimes something is attributed to or removed from a universal by reason of the particular. In order to designate this, in affirmative predications the term “some [aliquis] or “a certain one [quidam]” has been invented to designate that the predicate is attributed to the universal subject by reason of the particular, but since they do not signify the form of any singular determinately, it designates the singular under a certain indetermination, which is why it is called a “vague individual.” In negative predications, there is no designated term, but we can use the expression “not all [non omnis].”  Just as “no” removes universally, for it signifies the same thing as saying “not any,” that is, “not some,” so likewise “not all” removes in a particular way, since it excludes universal affirmation.

14] Therefore, there are three kinds of affirmations in which something is predicated of a universal. One is where something is predicated of the universal universally, as when one says “Every human is an animal.”  The second is where something is predicated of the universal particularly, as when one says “Some humans are white.” The third is where something is predicated of the universal, but without determination of universality or particularity. Propositions of this kind are usually called indefinite. There are the same number of negations opposed to them.

15] In the case of the singular, although something is predicated for a different reason, as was said above, nevertheless the whole is referred to its singularity, because the universal nature is individuated in the singular.  Therefore, it makes no difference to the nature of the singular whether something is predicated of the singular by reason of its universal nature, as in “Socrates is a human,” or belongs to it by reason of its singularity [as, “Socrates is Socrates”].

16] Therefore, if we add the singular to the three already mentioned kinds of propositions, there will be four kinds of propositions as far as their quantity goes:  universal, singular, indefinite, and particular.

13] Sicut autem supra dictum est, quandoque aliquid attribuitur universali ratione ipsius naturae universalis; et ideo hoc dicitur praedicari de eo universaliter, quia scilicet ei convenit secundum totam multitudinem in qua invenitur; et ad hoc designandum in affirmativis praedicationibus adinventa est haec dictio, omnis, quae designat quod praedicatum attribuitur subiecto universali quantum ad totum id quod sub subiecto continetur. In negativis autem praedicationibus adinventa est haec dictio, nullus, per quam significatur quod praedicatum removetur a subiecto universali secundum totum id quod continetur sub eo. Unde nullus dicitur quasi non ullus, et in Graeco dicitur, udis quasi nec unus, quia nec unum solum est accipere sub subiecto universali a quo praedicatum non removeatur. Quandoque autem attribuitur universali aliquid vel removetur ab eo ratione particularis; et ad hoc designandum, in affirmativis quidem adinventa est haec dictio, aliquis vel quidam, per quam designatur quod praedicatum attribuitur subiecto universali ratione ipsius particularis; sed quia non determinate significat formam alicuius singularis, sub quadam indeterminatione singulare designat; unde et dicitur individuum vagum. In negativis autem non est aliqua dictio posita, sed possumus accipere, non omnis; ut sicut, nullus, universaliter removet, eo quod significat quasi diceretur, non ullus, idest, non aliquis, ita etiam, non omnis, particulariter removeat, in quantum excludit universalem affirmationem.

14] Sic igitur tria sunt genera affirmationum in quibus aliquid de universali praedicatur. Una quidem est, in qua de universali praedicatur aliquid universaliter; ut cum dicitur, omnis homo est animal. Alia, in qua aliquid praedicatur de universali particulariter; ut cum dicitur, quidam homo est albus. Tertia vero est, in qua aliquid de universali praedicatur absque determinatione universalitatis vel particularitatis; unde huiusmodi enunciatio solet vocari indefinita. Totidem autem sunt negationes oppositae.

15] De singulari autem quamvis aliquid diversa ratione praedicetur, ut supra dictum est, tamen totum refertur ad singularitatem ipsius, quia etiam natura universalis in ipso singulari individuatur; et ideo nihil refert quantum ad naturam singularitatis, utrum aliquid praedicetur de eo ratione universalis naturae; ut cum dicitur, Socrates est homo, vel conveniat ei ratione singularitatis.

16] Si igitur tribus praedictis enunciationibus addatur singularis, erunt quatuor modi enunciationis ad quantitatem ipsius pertinentes, scilicet universalis, singularis, indefinitus et particularis

[Introductions and translations © R.E. Houser]

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