Michael Vernon Wedin

Aristotle claims in _Metaphysics_ Z.17 that form is both a cause and principle of c‐substances. In this chapter, Wedin argues that the explanatory, or causal, role of form is in the background of the entire discussion, and indeed directs much of the argumentation of _Metaphysics_ Zeta. Form is the cause of some matter being a unity and not a heap, because form alone explains how the material parts of a thing are united in a single whole. Wedin draws together the main results of the preceding investigation of Zeta—that form is essence, that form must not contain matter or actual parts, and that form must not be a certain kind of universal—and he argues that these constraints on form are designed to serve the explanatory role that Aristotle explicitly gives to form in Z.17. Wedin emphasizes that the notions isolated in the examination of the earlier chapters, such as the purity of form, weak proscription, and dual complexity, each contribute to the account of form as the explanatory principle of c‐substance.

Wedin offers an interpretation of _Metaphysics_ Zeta 13, a very important and difficult chapter, where Aristotle apparently denies that substance is a universal, having, on most accounts, already claimed that form is substance, and that form is a universal. This interpretation of the argument of Z.13, Wedin argues, threatens the possibility of attaining a definition of substance, and places in doubt what has gone before in the treatise. According to Wedin, what Aristotle is concerned with in Z.13 is not the denial that substance is a universal but rather with the denial that anything predicated universally of a c‐substance is the substance‐of the c‐substance, which Wedin calls ‘Weak proscription’. In Wedin's account of Z.13, then, Aristotle is continuing to pursue issues first raised in Z.10–11 that have to do with the relations between form and definition, and form and the universal. Wedin also argues that the dilemma at the conclusion of Z.13, regarding the definability of substance, is resolved in Z.16, with the notion of ‘Dual Complexity’, according to which the parts of a form exist potentially in the form, just as the parts of the c‐substance exist potentially in the c‐substance.

Chapters 10 and 11 are critical to the argument of _Metaphysics_ Zeta: these chapters are concerned with the purification of form. Z.10 introduces the apparatus of part and whole and consists of an argument to the end that form and its parts have priority over the other internal structural components of c‐substances, i.e. matter and the compound of form and matter; while in Z.11 Aristotle argues that form and its parts cannot involve any admixture of matter. Wedin argues that the causal role of form presupposes its purity: if form is to explain why a certain portion of matter constitutes a c‐substance of a given kind, then matter—whether this latter is understood as functional, or remnant matter—cannot already be contained in the form. This is the ‘purity thesis’, as Wedin calls it: matter cannot be included in the definitions of natural organisms, Wedin points out, because that would make the explanandum a part of the principle that explains it. Wedin also argues that form must be sufficiently complex to provide definitions of the natures of particular compounds, which are complex, even though form itself is a kind of universal.

Wedin discusses Aristotle's claims in _Metaphysics_ Zeta 6 that the essence of a thing is to be sought among its _per se_ attributes, and that each thing that is primary and spoken of _per se_, e.g. primary substance, is the same as its essence. Wedin argues that the Zeta 6 Thesis, i.e. that the essence of a thing is the thing's immediate essence, is a crucial requirement of the explanatory role of essence as the substance of c‐substances. According to Wedin, Aristotle introduces this requirement in order to establish that a thing's essence cannot depend on another essence. Form must be the essence; if form cannot explain the nature of the thing of which it is the form, there would be the threat of a regress of explanatory forms. At the end of the chapter, Wedin considers the problem that the identity of a thing and its essence is a requirement that can be met by non‐substance items, but he denies that this leads to a dilution of the conception of substance.

Wedin argues that Aristotle makes form the substance of c‐substances because it is the essence of the c‐substance. Much of this chapter consists of a careful examination of a passage in _Metaphysics_ Zeta 4, which Wedin calls the ‘New Primacy Passage’ (Z.4, 1030a2–17), that is crucial to Wedin's overall thesis, because here Aristotle appeals to a notion of definitional primacy, as opposed to the ontological primacy of the _Categories_. Z.4 focuses on this claim that form must be essence: Wedin argues that essence is a certain kind of form, a form of a genus (_genous eidos_); this does not mean ‘species’, as some commentators have thought. This is because the species is a combination of form and matter, whereas the _genous eidos_, Wedin argues, is the formal part only (i.e. the differentiae) of the definition that applies to the thing. On Wedin's account, Aristotle introduces the notion of explanatory primacy of form in Z.4.

In the _Metaphysics_, Aristotle often says that ‘form is substance’: in this chapter, Wedin argues that ‘substance’ in this context means the ‘substance‐of’ c‐substances. Wedin begins by examining Aristotle's use, and retention, of the framework of the _Categories_ in _Metaphysics_ Zeta (Z.1), before turning to discuss Z.3, which is crucial to understanding the relation between the _Categories_ and _Metaphysics_ theories of substance, because it is usually thought that here Aristotle departs from the substance of the _Categories_. Wedin denies that Z.3 involves a rejection of the _Categories_ subjecthood criterion for primary substance: Aristotle rejects only the claim that one thing is the substance of another simply if it is the primary underlying subject of the other. Wedin argues that in Z.3 Aristotle introduces the idea of the ‘substance‐of’ a thing, and identifies as candidates for the substance of c‐substances the internal structural components form, matter, and the compound of form and matter.

Wedin considers the problem of the compatibility of the _Categories_ account of primary substance with the theory of substantial form of the _Metaphysics_. Wedin collects from the secondary literature the most important arguments for incompatibilism, and offers some proposals for restoring their harmony. While admitting the evident differences in the way Aristotle treats the question of substance in each treatise, Wedin is keen to argue that these differences are not sufficient to conclude that the treatises are incompatible. Wedin singles out for particular attention, and criticism, Michael Frede and Gunther Patzig's account of _Metaphysics_ Zeta, according to which the primary substance of the _Metaphysics_ and the basic subject of predications is the form. Wedin considers two ‘philosophical’ arguments and one ‘Aristotelian’ argument for the subjecthood of forms, and argues that the textual evidence does not support the claim that form is the subject of accidents.

Wedin considers the relation between the ontological commitment in the _Categories_ and the semantical theory of underlying ontological configurations for standard categorical statements. According to Wedin, Aristotle's fourfold division of beings, which divides things according to whether they are, or are not, said of, and/or present in a subject, is a meta‐ontology that is concerned with beings _per se_, i.e. the fundamental things that are. Wedin explains that the primacy of c‐substance involves an asymmetry in the relation between c‐substance and everything else, or between the substantial and the nonsubstantial. This is because there is an ontological dependence of non‐substances, and also of secondary substances, on substances: everything is either said of, or in, primary substance. The argument of this chapter, then, is that the world of the _Categories_ is a world of individuals: all ontological relations needed for semantics can be accommodated by appeal to individuals only.

Wedin addresses the debate over whether nonsubstantial individuals, that inhere in a subject but are not said of a subject, i.e. accidents, such as the pallor of Socrates, are nonrecurring particulars or a kind of determinate universal. Wedin examines the secondary literature on this topic and divides it into two schools of thought, determined by the contributions of J.L. Ackrill and G.E.L. Owen. According to Ackrill, individuals in non‐substance categories are particular to the substance they are in; Owen critiques Ackrill's view, and proposes that these items can recur in more than one subject and hence are a sort of universal. Wedin finds Owen's thesis unsatisfactory, even after supplementing it with an improved version due to Michael Frede; instead, Wedin argues for a revised version of Ackrill's interpretation of nonsubstantial individuals as nonrecurrent particulars. According to Wedin, Aristotle is committed to individuals only—e.g. to Socrates and to the particular bit of pallor in him: this conclusion has an important bearing on the ontological status of individuals and on the primacy of substance to nonsubstantial items.

Wedin argues, against prevailing opinions, that Aristotle's account of homonymy, synonymy, and paronymy, with which the _Categories_ begins, must be understood as an integral part of the treatise. The three ‘onymyies’, as Wedin calls them, are grouping principles, or one‐over‐many principles, that each collect a number of items under a single term. Wedin focuses on synonymy in particular, because it enables Aristotle to construct a theory of the fundamental kinds of things that are, and as such provides the basis for the system of the categories. For Wedin, the _Categories_ is not just concerned with classification but also with ontology and semantics: it offers a theory about the underlying ontological implications of standard categorical statements, with the aim of determining what must exist, and in what relations these things must stand, in order for the statements to be true.

Wedin's main point in this book is that the question of _Metaphysics_ Zeta, ‘what is substance?’, should be understood as the question, ‘what is the substance of c‐substances?’. In other words, in virtue of what are the substances of the _Categories_ the sort of things they are—in virtue of what do they have the central, salient features mentioned but not explained in the _Categories_? Aristotle's answer is that it is in virtue of a structural component of the c‐substance—the form: form, then, is primary substance, but this primacy is explanatory and not ontological. Thus, in Zeta, c‐substances are subjected to hylomorphic analysis, i.e. in terms of form and matter, two entities that are not even mentioned in the _Categories_: for Wedin this shows that Aristotle in the _Categories_ has no interest in the structure of primary substances, because it is irrelevant to the purpose of the treatise. Hence, the treatises are complementary because ontological primacy is given to c‐substances, and explanatory primacy to their forms.

It is argued that Wittgenstein did not abandon his tractarian position because he was of the opinion that the Tractatus suffered from an intemal incoherence inherited from the incompatibility of the thesis of mutual independence of elementary propositions (MI) and the picture theory of the proposition (PIC) or an incoherent notion of the elementary proposition itself. In the way suggested, TLP provides no opportunity for such concems to arise, for the inner sub-surface structure of a proposition cannot cause conflict with MI. It rather was the sub-surface nature of elementary propositions itself - a feature fundamental to the Tractatus as a whole - Wittgenstein came to be dissatisfied with and gave up in favour of a new notion of elementary proposition.

Book Gamma of Aristotle’s Metaphysics contains a vigorous defense of the principle of non-contradiction (PNC). A chief part of Aristotle’s strategy is to attack those, such as Heraclitus and Protagoras, who are said to deny the principle. Commentators have found a number of logical and historical problems with Aristotle’s arguments, but none are more troubling than those he deploys against Protagoras. Midway through Gamma 4, and throughout Gamma 5, he represents Protagoras not as simply denying PNC but rather as asserting the contrary of the principle. The latter, the proposition that every thing has every property and its negation, I call the strong denial of PNC. In particular, Aristotle argues that Protagoras is committed to strong denial because of ‘Protagorean’ relativism – the doctrine that if something appears to be the case, then it is the case. This paper provides a reconstruction of Aristotle’s arguments in Gamma 4 and 5, and suggests that the second argument may infact hold against the Protagorean.

Aristotle's views on the fundamental nature of reality are usually taken to be inconsistent. The two main sources for these views are the Categories and the central books of the Metaphysics, particularly book Zeta. In the early theory of the Categories the basic entities of the world are concrete objects such as Socrates: Aristotle calls them 'primary substances'. But the later theory awards this title to the forms of concrete objects. Michael Wedin proposes a compatibilist solution to this long-standing puzzle, arguing that Aristotle is engaged in quite different projects in the two works. The theory of Metaphysics Zeta is meant to explain central features of the standing doctrine of the Categories, and so presupposes the essential truth of the early theory. The Categories offers a theory of underlying ontological configurations, while book Zeta gives form the status of primary substance because it is primarily the form of a concrete object that explains its nature, and this form is the substance of the object. So when the late theory identifies primary substance with form, it appeals to an explanatory primacy that is quite distinct from the ontological primacy that dominates the Categories. Wedin's new interpretation thus allows us to see the two treatises as complementing each other: they are parts of a unified history of substance.

This paper considers I) whether Aristotle's notion of form is 'compositionally plastic' and II) whether matter is in any way to be included in the form of natural things. It pursues (I) and (II) with respect to two texts only: De Anima I-2's socalled definition of anger and the notorious young Socrates passage from Metaphysics VII.11. Neither passage supports indusion of anything material in the form and both are consistent with compositional plasticity. To thus extent the support what I call the purification of form