2:30-3:30pm Alfonso Ganem (National University in Mexico City (UNAM) - ‘Al-Farabi on Foreknowledge and Contingency’
3:30-4:30pm Stephen Read (St Andrews) – ‘Curry paradoxes in medieval logic'
4:30-5:00pm Coffee break
5:00-6:00pm Sonja Schierbaum (Hamburg) – ‘Ockham and Chatton on demonstratives and (definite) descriptions’
Alfonso Ganem – ‘Al-Farabi on Foreknowledge and Contingency’
The tensions between determinism and free will in the Medieval Arabic tradition were common within the main theological schools, namely, Mu'tazilites and Ash'arites. The major debate between these schools is focused on the causal nature of agents and the degree of responsibility that can be attributed to their actions. The Mu'tazilites held a non-deterministic position according to which human beings are the agents of their own actions and can be responsible for their practical consequences. On the other hand, the Ash'arites recognized God as the unique agent of every event in the world and, hence, human actions were considered as secondary causes determined by Divine Will. The presence of Aristotelian, Neoplatonic and Stoic philosophy in the Arabic context introduced new conceptual and methodological tools that modified the standard interpretation of the debate and allowed the formulation of new solutions. The influence of ancient discussions on the different conceptions of causality and agency, providence, and the distinction between different kinds of necessity and possibility, allowed the development of a set of arguments different from the ones sustained by the theological schools. Arabic philosophers knew several versions of the conflict between determinism and free will coming from the Greek tradition, from deterministic positions such as that of the Stoics, to compatibilist positions such as that of the Peripatetics. Al-Farabi's approach to this difficulty introduces relevant nuances. The aim of this paper is precisely to reconstruct and analyze Al-Farabi's compatibilist argument as is presented in the second section of his Long Commentary on Peri Hermeneias. There, Al-Farabi argues for the compatibility between the epistemic access of the First Cause to future events and the contingent nature of sublunary events. The argument can be presented as a dilemma: the first horn sustains that the actions of sub-lunar substances cannot be determined because of a “principle of contingency" that characterizes their nature; the second horn defends the epistemic privilege of a God whose omnipotence let him know everything that exists in reality without any deficiency or indeterminacy. The first horn is grounded in a reductio ab absurdum that proves the existence of a principle of contingency in all material substances, implying an indeterminate “truth value" of any proposition about the future that refers to particular individuals. Therefore, the “truth value" of propositions with particular quantifiers and future operators cannot be determined by any logical method or be known by any epistemic agent. The second horn depends on an emanationist model that would allow for epistemic access to the complete set of propositions. The Long Commentary on Peri Hermeneias does not provide a clear description on the mode the First Cause intellects the world or the propositions, but we can use some of the arguments of the Perfect State to complete the vision of Al-Farabi's argument. The answer to the dilemma will be a logical solution that harmonizes divine fore-knowledge with the principle of contingency. Intellection of the determinate truth value of propositions does not imply the necessary elimination of contingency in natural facts, because the material modality of possibility in propositions is not affected by divine intellection. Therefore if God knows that “Zaid will travel tomorrow" or that “there will be a sea battle tomorrow", the principle of contingency can be preserved because the material aspects that compose the fact are in themselves indeterminate, while divine knowledge intellects the causal relation between propositions that makes it possible to know the fact determinately at a propositional level. In the paper, I reconstruct Al-Farabi's attempt to harmonize divine knowledge and the contingency of sub-lunar substances.
Stephen Read – ‘Curry paradoxes in medieval logic'
Recent work on the semantic paradoxes has focussed on V-Curry, a validity version of Curry's paradox, originally a set-theoretic paradox, due to Haskell B. Curry. Variants on this paradox were known to fourteenth-century logicians, who proposed their own solutions. Thomas Bradwardine's solution depends on the idea that every sentence signifies many things, and a sentence's truth depends on things' being wholly as it signifies. This definition of truth involves a rethinking of the T-scheme or truth-equivalence attributed to Alfred Tarski. Bradwardine's solution is underpinned by a novel theory of meaning, based on his claim that a sentence signifies everything that follows from it. The upshot is that solving the Curry and other semantic paradoxes does not require revision of logic, thus saving logic from paradox.
Sonja Schierbaum – ‘Ockham and Chatton on demonstratives and (definite) descriptions’
Walter Chatton is commonly considered as one of William Ockham’s earliest and most vehement critics. For instance, Chatton criticizes and finally rejects Ockham’s well known conception of intuition as a kind of intellectual perception of particulars (this dog, this blue spot). In this paper I want to discuss some implications of either embracing or rejecting intuition for the conception of our ways of thinking about particulars. I argue that Ockham denies that one can think about a particular only by means of some description. The point is that in his view knowing a thing a by intuition does not imply knowing a to be the referent of any description. Rather, knowing a by intuition implies merely the possibility of demonstrative identification. By contrast, it (partly) follows from Chatton’s rejection of intuition that according to him thinking about a particular always involves some description, even in case of demonstrative identification. The aim is to give a general assessment of the plausibility of these two positions regarding the “descriptive” and “non-descriptive” ways of thinking about particulars.