Christian Pfeiffer explores an important, but neglected topic in Aristotle's theoretical philosophy: the theory of bodies. A body is a three-dimensionally extended and continuous magnitude bounded by surfaces. This notion is distinct from the notion of a perceptible or physical substance. Substances have bodies, that is to say, they are extended, their parts are continuous with each other and they have boundaries, which demarcate them from their surroundings. Pfeiffer argues that body, thus understood, has a pivotal role in Aristotle's natural (...) philosophy. A theory of body is a presupposed in, e.g., Aristotle's account of the infinite, place, or action and passion, because their being bodies explains why things have a location or how they can act upon each other. The notion of body can be ranked among the central concepts for natural science which are discussed in Physics III-IV. (shrink)

Aristotle's notion of matter has been seen either as unintelligible, it being some mysterious potential entity that is nothing in its own right, or as simply the notion of an everyday object. The latter is the common assumption in contemporary approaches to hylomorphism, but as has been pointed out, especially by scholars with a background in ancient philosophy, if we conceive of matter as an object itself we cannot account for the unity of hylomorphic substances. Thus, they assume that a (...) hylomorphic substance is an essential unity and matter not a constituent at all. This solution to the problem of unity, however, brings us back to the mysterious notion of matter. For these reasons, I will revisit Aristotle's conception of matter in this paper. I will argue that an understanding of form as a cause of being requires that matter be an independent constituent of the individual substance. However, I agree that the conception of matter as an individual object with an essence makes it impossible to solve the problem of unity. We therefore need to take seriously Aristotle's assertion that matter is nothing in its own right and not an individual. By denying that matter is an individual, Aristotle does not introduce a mysterious entity, nor does he deny that it can be identified independently of the whole; instead, matter for Aristotle is an irreducible plurality, and this explains why it is not an individual and has no essence. I will conclude with some observations on how this gives rise to two competing versions of hylomorphic constitution. (shrink)

According to Aristotle, the way in which the parts of a whole are is different from the way in which the whole exists. Parts of an object are only potentially, whereas the whole exists actually. Although commentators agree that Aristotle held this doctrine, little effort has been made to spell out precisely what it could mean to say that the parts are only potentially. In this paper, I shall attempt to elucidate that claim and explain the philosophical motivation behind it. (...) I will argue that the motivation of mereological potentialism is to account for the unity of material substance. For a part to be potentially is, I will argue, a form of ontological dependence of the part on the whole. Potential parts have their being as a possible division of the whole. I will further explain this by specifying how the parts are grounded in the capacities of the whole and how the parts are individuated by the whole. (shrink)

I argue that Metaphysics H.6 is not an isolated chapter but the conclusion of an argument begun in H.3. This view will provide further and better arguments for the following view about long-standing interpretative debates: first, Aristotle provides a substantive account of the unity of the composite substance (although he also briefly addresses the unity of the form); second, neither Aristotle’s conception of matter nor his account of form changes between H.1–5 and H.6; and third, H does not rely on (...) and is not completed by book Θ in any significant way. (shrink)

In his paper, Josh Hayes argues that inclination (ῥοπή) is the nature of each element. It is an active and passive principle that explains why the elements move to their proper places. Thus, according to Hayes, by introducing inclination in De Caelo IV 1, Aristotle posits a single explanatory factor that accounts for all elemental motions. By doing so, he answers the question, posed in Physics VIII 4, of what the cause of elemental motion is. In my comments, I will (...) contest these claims. Aristotle’s theory of elemental motion does not rely on a single explanatory factor; yet, it is not, as Hayes claims, incoherent. Instead, the different strands merely reflect the special nature of the elements. (shrink)

: In this paper we give a detailed reconstruction of the first chapter of De Caelo I.1. Aristotle attempts to prove there that bodies are complete and perfect in virtue of being extended in three dimensions. We offer an analysis of this argument and argue that it gives important insight into the role the notion of body plays in physical science. Contrary to other interpretations, we argue that it is an argument about physical, as opposed to mathematical, bodies and that (...) the perfection and completeness of bodies is due to their nature. Moreover, Aristotle heavily relies in his proof on the premise that the number three implies perfection, a view he ascribes to the Pythagoreans. We review the possible sources of this view, as well as its role in Aristotle’s argumentative strategy. (shrink)

Im Vergleich zu seiner Ontologie und Ethik haben Aristoteles’ Überlegungen zur Philosophie des Geistes die moderne Philosophie weniger stark beeinflusst, und die meisten modernen Theorien wurden weitestgehend ohne expliziten Rückgriff auf Aristoteles entwickelt. Dennoch bleibt die aristotelische Philosophie des Geistes für viele heutige Debatten von großer Relevanz, sei es, dass sie als ein unmittelbarer Vorläufer moderner Theorien begriffen wird, sei es, dass sie gerade aufgrund der Verschiedenheit ihrer Annahmen als Alternative gesehen wird.