There is a traditional conception of knowledge but it is not the Justified True Belief analysis Gettier attacked. On the traditional view, knowledge consists in having a belief that bears a discernible mark of truth. A mark of truth is a truth-entailing property: a property that only true beliefs can have. It is discernible if one can always tell that a belief has it, that is, a sufficiently attentive subject believes that a belief has it if and only if it (...) has it. Requiring a mark of truth makes the view infallibilist. Requiring it to be discernible makes the view internalist. I call the view Classical Infallibilism. (shrink)

Medieval epistemology begins as ideal theory: when is one ideally situated with regard to one's grasp of the way things are? Taking as their starting point Aristotle's Posterior Analytics, scholastic authors conceive of the goal of cognitive inquiry as the achievement of scientia, a systematic body of beliefs, grasped as certain, and grounded in demonstrative reasons that show the reason why things are so. Obviously, however, there is not much we know in this way. The very strictness of this ideal (...) in fact gives rise to a body of literature on how Aristotle's framework might be relaxed in various ways, for certain specific purposes. In asking such questions, scholastic authors are in effect pursuing the project of social epistemology, by trying to adapt their ideal theory to the circumstances of everyday life. (shrink)

This paper studies John Buridan's octagons of opposition for the de re modal propositions and the propositions of unusual construction. Both Buridan himself and the secondary literature have emphasized the strong similarities between these two octagons (as well as a third one, for propositions with oblique terms). In this paper, I argue that the interconnection between both octagons is more subtle than has previously been thought: if we move beyond the Aristotelian relations, and also take Boolean considerations into account, then (...) the strong analogy between Buridan's octagons starts to break down. These differences in Boolean structure can already be discerned within the octagons themselves; on a more abstract level, they lead to these two octagons having different degrees of Boolean complexity (i.e. Boolean closures of different sizes). These results are obtained by means of bitstring analysis, which is one of the key tools from contemporary logical geometry. Finally, I argue that this historical investigation is directly relevant for the theoretical framework of logical geometry, and discuss how it helps us to address certain open questions in this framework. (shrink)

Jean Buridan developed his theory of consequence within a semantical framework compatible with what we now call token-based semantics. In his Treatise on Consequences and Sophismata, Buridan showed...

The essay first makes some observations on the general interrelationship between the logical writings of Albert and Buridan. Second, it gives an account of a ‘semantic logical model’ for analyzing complex subject terms in some basic categorical propositions which is defended by Albert of Saxony, and briefly recounts Buridan's criticisms of that model. Finally, the essay maintains that the Albertian model is typically compatible with, and a further development of, what is called by a late-fourteenth century anonymous scholar ‘the English-Rule’ (...) but the ‘determinable/determinate’ grammatical model defended by Buridan is not. (shrink)

ABSTRACT This paper explores some key features of Medieval accounts of intuition, focusing on Thomas Aquinas (1224/5–1274), on the one hand, and on Duns Scotus (c. 1266-1308), Peter Auriol (c. 1280–1322), and William Ockham (c. 1287-1347), on the other hand. The first section is devoted to the type of intuitive cognition which is accepted by all these authors, namely, the immediate and direct grasp of some present material object by the senses. It is from this basic sensory intuition – they (...) agree – that human cognition starts. The second section turns to intuitive intellectual cognition and to the much greater disagreements which divide these philosophers. Notwithstanding these important differences, the paper’s conclusion draws attention to the similarities in the conception of intuition which cut across the otherwise significantly different accounts of the authors discussed. I end with an invitation to recover their older way of thinking of intuition. (shrink)

An unconventional formalization of the canonical square of opposition in the notation of classical symbolic logic secures all but one of the canonical square’s grid of logical interrelations between four A-E-I-O categorical sentence types. The canonical square is first formalized in the functional calculus in Frege’s Begriffsschrift, from which it can be directly transcribed into the syntax of contemporary symbolic logic. Difficulties in received formalizations of the canonical square motivate translating I categoricals, ‘Some S is P’, into symbolic logical notation, (...) not conjunctively as \, but unconventionally instead in an ontically neutral conditional logical symbolization, as \. The virtues and drawbacks of the proposal are compared at length on twelve grounds with the explicit existence expansion of A and E categoricals as the default strategy for symbolizing the canonical square preserving all original logical interrelations. (shrink)

ABSTRACTThe aim of this paper is to challenge the reliabilist interpretation of William Ockham 's epistemology. The discussion proceeds as follows. First, I analyse the reliabilist interpretation into two theses: a negative thesis I call the Anti-Internalism Thesis, according to which, for Ockham, epistemic justification does not depend on any internal factors that are accessible by reflection; a positive thesis I call the Reliability Thesis, according to which epistemic justification in Ockham depends on the reliability of a causal process through (...) which a given judgment is produced. Secondly, I argue that the Anti-Internalism Thesis fails since Ockham's notion of evidentness, which is at the heart of his theory of justification, strongly suggests that he posits an indispensable, internalist element of justification. Lastly, I argue that the Reliability Thesis also fails since not only can there be a reliable but inevident judgment in Ockham's framework, his emphasis on causality is best read not as talk of reliability, but as his emphasis on the relation between reason and what is based on reason. (shrink)