Simo Knuuttila

(? - 2022)

Hugh of Novocastro, Landolfo Caracciolo, John Baconthorpe, and some other medieval authors argued that there are real contradictions in nature. The background of this early fourteenth-century theory was the Aristotelian question of how to determine the instant of change between p and ~p. The argument was that these are simultaneously true at the temporal instant of change if it is an instant of changing. The author’s aim is to discuss the background of this view in Henry of Ghent’s theory of instantaneous change from potentiality to actuality at that very instant.

The word "modem" in the title of this book refers primarily to post-medieval discussions, but it also hints at those medieval mo dal theories which were considered modem in contradistinction to ancient conceptions and which in different ways influenced philosophical discussions during the early modem period. The me dieval developments are investigated in the opening paper, 'The Foundations of Modality and Conceivability in Descartes and His Predecessors', by Lilli Alanen and Simo Knuuttila. Boethius's works from the early sixth century belonged to the sources from which early medieval thinkers obtained their knowledge of ancient thought. They offered extensive discus sions of traditional modal conceptions the basic forms of which were: (1) the paradigm of possibility as a potency striving to realize itself; (2) the "statistical" interpretation of modal no tions where necessity means actuality in all relevant cases or omnitemporal actuality, possibility means actuality in some rel evant cases or sometimes, and impossibility means omnitemporal non-actuality; and (3) the "logical" definition of possibility as something which, being assumed, results in nothing contradic tory. Boethius accepted the Aristotelian view according to which total possibilities in the first sense must prove their met tle through actualization and possibilities in the third sense are assumed to be realized in our actual history. On these presump tions, all of the above-mentioned ancient paradigms imply the Principle of Plenitude according to which no genuine possibility remains unrealized.

The last twenty years have seen remarkable developments in our understanding of how the ancient Greek thinkers handled the general concept of being and its several varieties. The most general examination of the meaning of the Greek verb 'esti'/'einai'/'on' both in common usage and in the philosophical literature has been presented by Charles H. Kahn, most extensively in his 1973 book The Verb 'Be' in Ancient Greek. These discussions are summarized in Kahn's contribution to this volume. By and large, they show that conceptual schemes by means of which philosophers have recently approached Greek thought have not been very well suited to the way the concept of being was actually used by the ancients. For one thing, being in the sense of existence played a very small role in Greek thinking according to Kahn. Even more importantly, Kahn has argued that Frege and Russell's thesis that verbs for being, such as 'esti', are multiply ambiguous is ill suited for the purpose of appreciating the actual conceptual assumptions of the Greek thinkers. Frege and Russell claimed that a verb like 'is' or'esti' is ambiguous between the 'is' of identity, the 'is' of existence, the copulative 'is', and the generic 'is' (the 'is' of class-inclusion). At least a couple of generations of scholars have relied on this thesis and fre quently criticized sundry ancients for confusing these different senses of 'esti' with each other.

Many fourteenth-century logicians took affirmative propositions to maintain that the subject term and the predicate term stand or supposit for the same. This is called the identity theory of predication by historians and praedicatio identica by Paul of Venice and others. The identity theory of predication was an important part of early fourteenth-century Trinitarian discussions as well, but what was called praedicatio identica by Duns Scotus and his followers in this context was something different. After some remarks on Scotus’s view and its background, I shall analyse Adam Wodeham’s explanation of Scotus’s praedicatio identica and how he understood the assumptions pertaining to supposition in the Scotist approach. I also describe Wodeham’s own solution to Trinitarian sophisms, which did not deviate from the identity theory of predication.

In this article, I shall consider medieval discussions of the principles of Aristotelian syllogistic which were called the dictum de omni et nullo and the expository syllogism. I am particularly interested in how theological questions contributed to the introduction of some influential new medieval ideas, such as the extensional sameness of the subject as the basis of predication, the interpretation of the expository syllogism from this point of view, and the explication of the logical subject of universal and particular syllogistic premises with the phrase `Anything/something which is A. . .'. I end with some remarks about the increasing medieval awareness that these developments were beyond Aristotle's purview