The idea that some parts of reality are fundamental and others derivative was an important one in Aristotle's philosophical system, and is now again of great current interest in philosophy. Michail Peramatzis presents a new account of priority relations in Aristotle's metaphysics, and draws out their continuing philosophical significance.

Michail Peramatzis presents a new interpretation of Aristotle's view of the priority relations between fundamental and derivative parts of reality, following the recent revival of interest in Aristotelian discussions of what priority consists in and how it relates existents. He explores how in Aristotle's view, in contradistinction with (e.g.) Quinean metaphysical views, questions of existence are not considered central. Rather, the crucial questions are: what types of existent are fundamental and what their grounding relation to derivative existents consists in. It is extremely important, therefore, to return to Aristotle's own theses regarding priority and to study them not only with exegetical caution but also with an acutely critical philosophical eye. Aristotle deploys the notion of priority in numerous levels of his thought. In his ontology he operates with the notion of primary substance. His Categories, for instance, confer this honorific title upon particular objects such as Socrates or Bucephalus, while in the Metaphysics it is essences or substantial forms, such as being human, which are privileged with priority over certain types of matter or hylomorphic compounds (either particular compound objects such as Socrates or universal compound types such as the species human). Peramatzis' chief aim is to understand priority claims of this sort in Aristotle's metaphysical system by setting out the different concepts of priority and seeing whether and, if so, how Aristotle's preferred prior and posterior items fit with these concepts.

The main objective of this Element is to reconstruct Aristotle's view on the nature of ontological priority in the Categories. Over the last three decades, investigations into ontological dependence and priority have become a major concern in contemporary metaphysics. Many see Aristotle as the originator of these discussions and, as a consequence, there is considerable interest in his own account of ontological dependence. In light of the renewed interest in Aristotelian metaphysics, it will be worthwhile - both historically and systematically - to return to Aristotle himself and to see how he himself conceived of ontological priority (what he calls 'priority in substance' [proteron kata ousian] or 'priority in nature' [proteron tēi phusei]), which is to be understood as a form of asymmetric ontological dependence.

The problem of the one and the many is central to ancient Greek philosophy, but surprisingly little attention has been paid to Aristotle's treatment of it in the Metaphysics. This omission is all the more surprising because the Metaphysics is one of our principal sources for thinking that the problem is central and for the views of other ancient philosophers on it.The Central Books of the Metaphysics are widely recognized as the most difficult portion of a most difficult work. Halper uses the problem of the one and the many as a lens through which to examine the Central Books. What he sees is an extraordinary degree of doctrinal cogency and argumentative coherence in a work that almost everyone else supposes to be some sort of patchwork. Rather than trying to elucidate Aristotle's doctrines-most of which have little explicitly to do with the problem, Halper holds that the problem of the one and the many, in various formulations, is the key problematic from which Aristotle begins and with which he constructs his arguments. Thus, exploring the problem of the one and the many turns out to be a way to reconstruct Aristotle's arguments in the Metaphysics. Armed with the arguments, Halper is able to see Aristotle's characteristic doctrines as conclusions. These latter are, for the most part, supported by showing that they resolve otherwise insoluble problems. Moreover, having Aristotle's arguments enables Halper to delimit those doctrines and to resolve the apparent contradiction in Aristotle's account of primary ousia, the classic problem of the Central Books. Although there is no way to make the Metaphysics easy, this very thorough treatment of the text succeeds in making it surprisingly intelligible.

Cleary discusses the origin, development, and use of the many senses of priority as a central thesis in Aristotle's metaphysics. Cleary contends that one of the most revealing problems for the ambiguity of Aristotle's relationship to Platonism is that of the ontological status of mathematical objects. In support of his claim, Cleary analyzes a curious passage from Aristotle's Topics, where he appears to accept a schema of priorities that makes mathematical entities more substantial than sensible things. How does Aristotle try to reconcile the ordering of things dictated by sciences like mathematics and dialectic with the ordering of sense experience upon which his own physics and metaphysics are based? To find the answer, Cleary reviews three different outlines of the many senses of priority given by Aristotle himself and found in Categories 12-13, Metaphysics Delta 11, and Metaphysics Theta 8. Cleary suggests there is an implicit hierarchy for Aristotle that leads him to posit the Prime Mover at its apex as complete actuality and, therefore, as the focus for the concept of priority. Having reviewed Aristotle's treatment of the many uses of priority, Cleary demonstrates how the concept is used in some typical arguments by Aristotle for his mature metaphysical positions.

This volume presents fourteen new essays by leading figures in the fields of ancient philosophy and contemporary metaphysics, discussing Aristotle's theory of the unity of substances. This topic remains at the centre of metaphysical enquiry.The contributors examine the nature of essences, how they differ from other components of substance, and how they are related to these other components. The central questions discussed here are: What does Aristotle mean by 'potentiality' and 'actuality'? How do these concepts explicate matter andform, and how are they related to the actuality of substance? What is the role of matter and form in accounting for the unity, identity, and individuation of substances? These questions are crucial to an understanding of the unity of composite substances and their identity over time.The aim of the volume is both exegetical and philosophical: to address central issues in Aristotle's Metaphysics, and to stimulate further investigation of the problems and controversies that arise from these.

Charlotte Witt continues her highly regarded exploration of Aristotle's metaphysics in a book devoted to the ontological distinction between potentiality and actuality. She focuses on Metaphysics book ix, which provides the most sustained discussion of this distinction. Witt rejects the conventional reading of this key text—that Aristotle differentiated between the two concepts solely to further the investigation of substance. Instead, in an original interpretation of his work, she argues that his development of the distinction between "being x potentially" and "being x actually" allowed Aristotle to develop an intrinsically hierarchical and normative vision of reality.For Witt, Aristotle's views about being shed light on his puzzling use of gender language in his descriptions of reality. This language has become an important issue for feminist scholars who have noted that in Aristotle's metaphysics of substance form is sometimes associated with the male, and matter with the female. Witt's interpretation that Aristotelian reality is intrinsically hierarchical and normative, but not intrinsically gendered, offers a new, important understanding of a controversial aspect of Aristotle's metaphysics.