The Significance of the Universal ut nunc

THE SIGNIFICANCE OF THE UNIVERSAL UT NUNC IN his commentary on the Posterior Analytics of Aristotle, St. Thomas notes that dici de omni, sometimes translated as "true in every instance," is treated differently in the Posterior Analytics from the way it is in the Prior Analytics. In the latter work, which is concerned with the form of the syllogism and therefore with what is common to any syllogism, dici de omni is treated only commonly, disregarding the differences attaching to a demonstrative or dialectical use. In this context, it is enough to say that dici de omni is realized whenever the predicate is found to be in each of those things which are contained under the subject. Once, however, we begin to consider the syllogism on the part of matter, we must say more about dici de omni. Hence, immediately after saying that the predicate is found in each of those things which are contained under the subject, St. Thomas adds: "This can happen either ut nunc, and in this way the dialectician sometimes uses dici de omni, or absolutely and for all time, and in this way only the demonstrator uses it." 1 In discussing the ancient and medieval theory of universals, we are apt to overlook this distinction between the verified dici de omni and the provisional one called universal ut nunc, and we tend to ignore the importance the latter has as a tool particularly for the investigation of nature. An example of the verified dici de omni was the common property of every parabolic triangle, ' to have its three angles equal to two right angles.' An instance of the universal ut nunc was ' white ' predicated as a common property of swans. The former property was based upon a propter quid demonstration; the latter was based upon, or rather derived from, an incomplete 1 " Hoc autem contingit vel ut nunc, et sic utitur quandoque dici de omni dialecticus ; vel simpliciter et secundum omne tempus, et sic solum utitur eo demonstrator ." In I Post. Anal., lect. 9, n. 4. 168 164 JOHN A. OESTERLE induction: no one reporting about swans had ever seen a black one. We come therefore at once to the following question. Since " white," as a common property, was not certain, why is it that we could use the universally distributive ' all ' and say that all swans are white? Why not use a roundabout expression and state: "It appears that some, if not all, swans are white." Or why not say, even more simply, " swan is white," as we say " man is white." In this more simple way of putting the matter we would be plainly predicating something of a universal (" swan ") by reason of something found in one or some individuals. The point then is whether this would be regarded as a universal ut nunc, a universal " for the time being." Presumably not, for what we are aiming at is an enunciation like "man is an animal," an essential predication. But why use this mode of enunciation before it is warranted? What we are in fact faced with is two distinct modes of essential predication: a true one and a hypothetical one. What is the foundation for this distinction? Why are hypothetically essential predications required? Why not use unambiguous circumlocutions that show the essential predication to be only hypothetical? After all, many essential predications are in fact no more than hypothetical. To answer such questions-which in effect are one questionabout the distinction between true and hypothetical essential predications, it will be opportune, first of all, to make a further distinction by comparing the notion of " triangle " with what we intend by" swan." We can define the first as to what it is, namely a three straight-sided figure whose exterior angle is equal to the two opposite interior angles. But what about "swan"? We define, not the swan, but the name by pointing to individual instances, or by describing the figure and habits that set swans apart from chickens, turkeys, geese, and so on. Now surely there must be in nature something that accounts SIGNIFICANCE OF THE UNIVERSAL .. UT NUNC" 165 for these differences. But what is this exactly? As St. Thomas says...