This paper sets out to evaluate the claim that Aristotle’s Assertoric Syllogistic is a relevance logic or shows significant similarities with it. I prepare the grounds for a meaningful comparison by extracting the notion of relevance employed in the most influential work on modern relevance logic, Anderson and Belnap’s Entailment. This notion is characterized by two conditions imposed on the concept of validity: first, that some meaning content is shared between the premises and the conclusion, and second, that the premises (...) of a proof are actually used to derive the conclusion. Turning to Aristotle’s Prior Analytics, I argue that there is evidence that Aristotle’s Assertoric Syllogistic satisfies both conditions. Moreover, Aristotle at one point explicitly addresses the potential harmfulness of syllogisms with unused premises. Here, I argue that Aristotle’s analysis allows for a rejection of such syllogisms on formal grounds established in the foregoing parts of the Prior Analytics. In a final section I consider the view that Aristotle distinguished between validity on the one hand and syllogistic validity on the other. Following this line of reasoning, Aristotle’s logic might not be a relevance logic, since relevance is part of syllogistic validity and not, as modern relevance logic demands, of general validity. I argue that the reasons to reject this view are more compelling than the reasons to accept it and that we can, cautiously, uphold the result that Aristotle’s logic is a relevance logic. (shrink)

At least since Socrates, philosophy has been understood as the desire for acquiring a special kind of knowledge, namely wisdom, a kind of knowledge that human beings ordinarily do not possess. According to ancient thinkers this desire may result from a variety of causes: wonder or astonishment, the bothersome or even painful realization that one lacks wisdom, or encountering certain hard perplexities or aporiai. As a result of this basic understanding of philosophy, Greek thinkers tended to regard philosophy as an (...) activity of inquiry (zētēsis) rather than as a specific discipline. Discussions concerning the right manner of engaging in philosophical inquiry – what methodoi or routes of inquiry were best suited to lead one to wisdom – became an integral part of ancient philosophy, as did the question how such manners or modes of inquiry are related to, and differ from, other types of inquiry, for instance medical or mathematical. In this special issue of History of Philosophy & Logical Analysis, we wish to concentrate in particular on ancient modes of inquiry. (shrink)

It is commonly assumed that Aristotle thinks that his claim that being exhibits a category-based pros hen structure, which he introduces to obviate the problem of categorial heterogeneity, is sufficient to defend the possibility of a science of being qua being. We, on the contrary, argue that Aristotle thinks that the pros hen structure is necessary only, but not sufficient, for this task. The central thesis of our paper is that Aristotle, in what follows 1003b19, raises a second problem for (...) the possibility of the science of being qua being; and that he does not think that the resolution of the first, the category-based problem, is either necessary or sufficient for resolving this problem. This is the problem: how can a plurality of apparently primary kinds and their opposites (they include to hen, to on, to auto, to homoion, to heteron and to anhomoion) be the subject-matter of the science of being qua being? It has been argued that these kinds are per se attributes of ousia and that, therefore, this problem is not different from the first problem. This, we argue, is mistaken; for nowhere in Gamma 2 does Aristotle claim that unity is a per se attribute of ousia. Rather, he says that identity, similarity, etc. are per se attributes of being qua being and unity qua unity. Aristotle’s resolution of the second problem, we argue, is that most of these kinds are reducible to a single compound principle: being-and-unity. Being and unity, moreover, are themselves related to each other as primary ousia and consequent ousia; but, we argue, Aristotle leaves it open, in Gamma 2, which of the two is primary, and which is consequent ousia. (shrink)