Metaphysics is sensitive to the conceptual tools we choose to articulate metaphysical problems. Those tools are a lens through which we view metaphysical problems, and the same problems will look different when we change the lens. In this book, Theodore Sider identifies how the shift from modal to "postmodal" conceptual tools in recent years has affected the metaphysics of science and mathematics. He highlights, for instance, how the increased consideration of concepts of ground, essence, and fundamentality has transformed the debate over structuralism in many ways. Sider then examines three structuralist positions through a postmodal lens. First, nomic essentialism, which says that scientific properties are secondary and lawlike relationships among them are primary. Second, structuralism about individuals, a general position of which mathematical structuralism and structural realism are instances, which says that scientific and mathematical objects are secondary and the pattern of relations among them is primary. And third, comparativism about quantities, which says that particular values of scientific quantities, such as having exactly 1000g mass, are secondary, and quantitative relations, such as being-twice-as-massive-as, are primary. Sider concludes these discussions by considering the meta-question of when theories are equivalent and how that impacts the debate over structuralism.

Many significant problems in metaphysics are tied to ontological questions, but ontology and its relation to larger questions in metaphysics give rise to a series of puzzles that suggest that we don't fully understand what ontology is supposed to do, nor what ambitions metaphysics can have for finding out about what the world is like. Thomas Hofweber aims to solve these puzzles about ontology and consequently to make progress on four central metaphysical problems: the philosophy of arithmetic, the metaphysics of ordinary objects, the problem of universals, and the question whether reality is independent of us. Crucial parts of the proposed solution include considerations about quantification and its relationship to ontology, the place of reference in natural languages, the possibility of ineffable facts, the extent of empirical evidence in metaphysics, and whether metaphysics can properly be esoteric. Overall, Hofweber defends a rationalist account of arithmetic, an empiricist picture in the philosophy of ordinary objects, a restricted from of nominalism, and realism about reality, understood as all there is, but idealism about reality, understood as all that is the case. He defends metaphysics as having some questions of fact that are distinctly its own, with a limited form of autonomy from other parts of inquiry, but rejects several metaphysical projects and approaches as being based on a mistake.

Laura Castelli presents a new translation of the tenth book (Iota) of Aristotle's Metaphysics, together with a comprehensive commentary. Castelli's commentary helps readers to understand Aristotle's most systematic account of what it is for something to be one, what it is for something to be a unit of measurement, and what contraries are.

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.

The Metaphysics presents Aristotle's mature rejection of both the Platonic theory that what we perceive is just a pale reflection of reality and the hardheaded view that all processes are ultimately material. He argued instead that the reality or substance of things lies in their concrete forms, and in so doing he probed some of the deepest questions of philosophy: What is existence? How is change possible? And are there certain things that must exist for anything else to exist at all? The seminal notions discussed in The Metaphysics - of 'substance' and associated concepts of matter and form, essence and accident, potentiality and actuality - have had a profound and enduring influence, and laid the foundations for one of the central branches of Western philosophy.

Idealism is a family of metaphysical views each of which gives priority to the mental. The best-known forms of idealism in Western philosophy are Berkeleyan idealism, which gives ontological priority to the mental (minds and ideas) over the physical (bodies), and Kantian idealism, which gives a kind of explanatory priority to the mental (the structure of the understanding) over the physical (the structure of the empirical world). Although idealism was once a dominant view in Western philosophy, it has suffered almost total neglect over the last several decades. This book rectifies this situation by bringing together seventeen essays by leading philosophers on the topic of metaphysical idealism. The various essays explain, attack, or defend a variety of idealistic theories, including not only Berkeleyan and Kantian idealisms but also those developed in traditions less familiar to analytic philosophers, including Buddhism and Hassidic Judaism. Although a number of the articles draw on historical sources, all will be of interest to philosophers working in contemporary metaphysics. This volume aims to spark a revival of serious philosophical interest in metaphysical idealism.