This paper concerns Aristotle's kind‐crossing prohibition. My aim is twofold. I argue that the traditional accounts of the prohibition are subject to serious internal difficulties and should be questioned. According to these accounts, Aristotle's prohibition is based on the individuation of scientific disciplines and the general kind that a discipline is about, and it says that scientific demonstrations must not cross from one discipline, and corresponding kind, to another. I propose a very different account of the prohibition. The prohibition is (...) based on Aristotle's scientific and metaphysical essentialism, according to which a scientific demonstration must take as its starting point a set of per se properties of a subject, if these make up a single, unitary definition. The subject of demonstration here is a kind, although not the general kind associated with a discipline, but rather the particular kind that the particular demonstration is about. (shrink)

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)

In Metaphysics Theta 3 Aristotle attributes to the Megarics and unknown others a notorious modal thesis: (M) something can φ only if it is φ-ing. Aristotle does not tell us what motivated (M). Almost all scholars take Aristotle’s report to indicate that the Megarics defended (M) as a highly counterintuitive doctrine in modal metaphysics. But this reading faces several problems. First: what would motivate the Megarics to hold such a counterintuitive view? The existing literature tries, in various ways, to motivate (...) (M) in a way neither trivial nor absurd. But, as we will argue, the main approaches end up attributing an unsustainable position to the Megarics. Second: most historical evidence for the Megaric lineage presents the group’s philosophical practice as dialectical or negative. So why think that the claim reported in Theta 3 presents a positive, and highly controversial, metaphysical claim? This paper addresses these problems by proposing a dialectical (or negative) reading of the Megarics in Theta 3. By ‘dialectical’ we here mean a mode of philosophizing that neither seeks to establish the truth or falsity of certain theses, nor takes a skeptical stance. There are different reasons why a philosopher might want to take up such a mode; in the case of the Megarics we argue that they might have wanted to put pressure on Aristotle’s idea of possibility and the ‘test’ for possibility that Aristotle mentions in several works. Reading, as we do, (M) as (part of) a paradox about possibility and actuality, we argue that the Megarics’ dialectical approach here aims to highlight a shortcoming of an intuitive conception of possibility, which underpins Aristotle’s idea of possibility and which features in his test for possibility. (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)

Dieser Band wirft ein neues Licht auf Byzanz - als geographischen, aber vor allem als kulturellen Knotenpunkt. Denn wie kaum eine andere Region ist Byzantium über gut ein Jahrtausend durch seine ebenso zentrale wie fragile geographische Lage, aber auch durch sein Prestige wichtig für die Begegnung von Kulturen, Personen und Institutionen rund um das Mittelmeer. Hierbei stellt sich aus byzantinischer Perspektive die "antike" und "mittelalterliche" Welt als ein in wesentlichen Zügen kontinuierlicher Kulturraum dar, der bis an die Schwelle der Neuzeit (...) reicht und sich vor allem durch seine große Rezeptivität auszeichnet. Thematisiert werden daher vor allem die Wechselseitigkeit kultureller und epistemischer Rezeptions- und Transformationsprozesse und ihre jeweiligen Wissensformen. Diese Wissensformen beziehen sich auf die Ordnungsstrukturen, die der Erkenntnis und den Wissenschaften, der Sprache und medialen Repräsentation sowie den institutionellen und soziologischen Bedingungen zugrundeliegen, sowie auf die diesen korrespondierenden Gegenstände des Wissens. In diesem Austausch begegnet Byzanz auch den transformierten Spuren, welche die griechische Kultur zuvor bei ihren eifrigen Nachahmern hinterlassen hat. (shrink)

In order to elucidate his logical analysis of modal quantified propositions (e.g. ‘all men are necessarily mortal’), the 14th century philosopher John Buridan constructed a modal octagon of oppositions. In the present paper we study this modal octagon from the perspective of contemporary logical geometry. We argue that the modal octagon contains precisely six squares of opposition as subdiagrams, and classify these squares based on their logical properties. On a more abstract level, we show that Buridan’s modal octagon precisely captures (...) the interaction between two classical squares of opposition, viz. one for the quantifiers and one for the modalities. Finally, we argue that several aspects of our contemporary formal analyses were already hinted at by Buridan himself. (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)