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.

Aristotle maintains that biological organisms are compounds of matter and form and that compounds that have the same form are individuated by their matter. According to Aristotle, an object that undergoes change is an object that undergoes a change in form, i.e. form is imposed upon something material in nature. Aristotle therefore identifies organisms according to their matter and essential forms, forms that are arguably essential to an object's existence. Jeremy Kirby addresses a difficulty in Aristotle's metaphysics, namely the possibility that two organisms of the same species might share the same matter. If they share the same form, as Aristotle seems to suggest, then they seem to share that which they cannot, their identity. By taking into account Aristotle's views on the soul, its relation to living matter, and his rejection of the possibility of resurrection, Kirby reconstructs an answer to this problem and shows how Aristotle relies on some of the central themes in his system in order to resist this unwelcome result that his metaphysics might suggest.

From its Presocratic beginnings, Western philosophy concerned itself with a quest for unity both in terms of the systematization of knowledge and as a metaphysical search for a unity of being—two trends that can be regarded as converging and culminating in Hegel's system of absolute idealism. Since Hegel, however, the philosophical quest for unity has become increasingly problematic. Jussi Backman returns to that question in this book, examining the place of the unity of being in the work of Heidegger. Backman sketches a consistent picture of Heidegger as a thinker of unity who throughout his career in different ways attempted to come to terms with both Parmenides's and Aristotle's fundamental questions concerning the singularity or multiplicity of being—attempting to do so, however, in a "postmetaphysical" manner rooted in rather than above and beyond particular, situated beings. Through his analysis, Backman offers a new way of understanding the basic continuity of Heidegger's philosophical project and the interconnectedness of such key Heideggerian concepts as ecstatic temporality, the ontological difference, the turn (Kehre), the event (Ereignis), the fourfold (Geviert), and the analysis of modern technology.

Reale's monumental work establishes the exact dimensions of Aristotle's concept of first philosophy and proves the profound unity of concept that exists in Aristotle's Metaphysics. Reale's opposition to the genetic interpretation of the Metaphysics is an updated return to a more traditional view of Aristotle's work, one which runs counter to nearly all contemporary scholarship. Reale argues that Aristotle's first philosophy includes a study of being, a study of substance, a study of divine substance, and a study of principles and causes, all of which are integrated and dialectically reconciled.

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.

A distinguished group of scholars of ancient philosophy here presents a systematic study of the twelfth book of Aristotle's Metaphysics. Lambda, which can be regarded as a self-standing treatise on substance, has been attracting particular attention in recent years, and was chosen as the focusof the fourteenth Symposium Aristotelicum, from which this volume derives. At the Symposium, each of Lambda's ten chapters was taken in turn as the subject of a session at which a specially written paper was read to and discussed by the assembled symposiasts. (The ninth chapter commanded twosessions by dint of its particular difficulty.) The papers have been revised in the light of discussion, and are now offered to a wider audience as a discursive commentary on points of particular philosophical interest covering all of Lambda. Michael Frede's extensive Introduction aims to give abroader view of Lambda as a whole and the problems it raises, and thus to provide the context for the discussion of each of the chapters. This volume will be a resource of great value and interest for anyone working on ancient metaphysics and theology.

In Aristotle's teleological view of the world, natural things come to be and are present for the sake of some function or end (for example, wings are present in birds for the sake of flying). Whereas much of recent scholarship has focused on uncovering the (meta-)physical underpinnings of Aristotle's teleology and its contrasts with his notions of chance and necessity, this book examines Aristotle's use of the theory of natural teleology in producing explanations of natural phenomena. Close analyses of Aristotle's natural treatises and his Posterior Analytics show what methods are used for the discovery of functions or ends that figure in teleological explanations, how these explanations are structured, and how well they work in making sense of phenomena. The book will be valuable for all who are interested in Aristotle's natural science, his philosophy of science, and his biology.