The contributions to this collection deal with the fundamental problem of unity, which plays a decisive role in many contemporary debates (even when this role is not acknowledged). Questions like whether there can be unities that persist through time ? e.g. persons who remain the same throughout their lives ? are discussed from various perspectives. Is such an idea possible at all, and if so, what role do concepts like force, capacity, and disposition play in this context?

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.

Leibniz’s metaphysics of space and time stands at the centre of his philosophy and is one of the high-water marks in the history of the philosophy of science. In this work, Futch provides the first systematic and comprehensive examination of Leibniz’s thought on this subject. In addition to elucidating the nature of Leibniz’s relationalism, the book fills a lacuna in existing scholarship by examining his views on the topological structure of space and time, including the unity and unboundedness of space and time. It is shown that, like many of his more recent counterparts, Leibniz adopts a causal theory of time where temporal facts are grounded on causal facts, and that his approach to time represents a precursor to non-tensed theories of time. Futch then goes on to situate Leibniz’s philosophy of space and time within the broader context of his idealistic metaphysics and natural theology. Emphasizing the historical background of Leibniz’s thought, the book also places him in dialogue with contemporary philosophy of science, underscoring the enduring philosophical interest of Leibniz’s metaphysics of time and space.

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.

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.

The quest for unity and multiplicity is one of the most important concerns in the history of human thought. Since the origins of the history of philosophy up to the present, we can observe more or less unceasing interest in the issue. The same holds of the writings of Thomas Aquinas, to whose conception this work is devoted. Since the problem of unity and multitude is closely linked to many other key metaphysical issues, such as the doctrine of transcendental concepts, the mode of composition of being qua being, as well as substantial and accidental being, or the doctrine of whole and part, we believe that its proper interpretation not only can clarify some partial metaphysical problem, but will also contribute to understanding the metaphysical thought of the Angelic Doctor as a whole.

"Lectures ... given at Harvard University in the first half of the academic year 1936-37"--Foreword.