Mary Louise Gill

Self-Motion: From Aristotle to Newton

The concept of self-motion is not only fundamental to Aristotles argument for the Prime Mover and to ancient and medieval theories of nature, but it is also central to many theories of human agency and moral responsibility. In this collection of essays, scholars of classical, Hellenistic, medieval and early modern philosophy and science explore the question of the existence of self-movers and their motivations. They trace the development of the concept of self-motion from its formulation in Aristotles metaphysics, cosmology and philosophy of nature through two millennia of philosophical, religious and scientific thought.

Aristotle’s Distinction between Change and Activity

Aristotle’s conception of being is dynamic. He believes that a thing is most itself when engaged in its proper activities, governed by its nature. This paper explores this idea by focusing on Metaphysics Θ, a text that continues the investigation of substantial being initiated in Metaphysics Z. Q.1 claims that there are two potentiality-actuality distinctions, one concerned with potentiality in the strict sense, which is involved in change, the other concerned with potentiality in another sense, which he says is more useful for the present project. His present project is the investigation of substantial being, and the relevant potentiality is the potentiality for activity, the full manifestation of what a thing is. I explore Aristotle’s two potentiality-actuality distinctions AND argue that the second distinction is modeled on the first, with one crucial modification. Whereas a change is brought about by something other than the object or by the object itself considered as other (as when a doctor cures himself), an activity is brought about by the object itself considered as itself. This single modification yields an important difference: whereas a change leads to a state other than the one an object was previously in, an activity maintains or develops what an object already is.

Aristotle on Substance: The Paradox of Unity

This book explores a fundamental tension in Aristotles metaphysics: how can an entity such as a living organisma composite generated through the imposition of form on preexisting matterhave the conceptual unity that Aristotle demands of primary substances? Mary Louise Gill bases her treatment of the problem of unity, and of Aristotles solution, on a fresh interpretation of the relation between matter and form. Challenging the traditional understanding of Aristotelian matter, she argues that material substances are subverted by matter and maintained by form that controls the matter to serve a positive end. The unity of material substances thus involves a dynamic relation between resistant materials and directive ends. Aristotle on Substance offers both a general account of matter, form, and substantial unity and a specific assessment of particular Aristotelian arguments. At every point, Gill engages Aristotle on his own philosophical ground through the detailed analysis of central, and often controversial, texts from the Metaphysics, Physics, On Generation and Corruption, De Anima, De Caelo, and the biological works. The result is a coherent, firmly grounded rethinking of Aristotles central metaphysical concepts and of his struggle toward a fully consistent theory of material substances.

Substance and Essence in Aristotle: An Interpretation of Metaphysics VII-IX

Substance and Essence in Aristotle is a close study of Aristotles most profound-and perplexing-treatise: Books VII-IX of the Metaphysics. These central books, which focus on the nature of substance, have gained a deserved reputation for their difficulty, inconclusiveness, and internal inconsistency. Despite these problems, Witt extracts from Aristotles text a coherent and provocative view about sensible substance by focusing on Aristotles account of form or essence. After exploring the context in which Aristotles discussion of sensible substance takes place, Witt turns to his analysis of essence. Arguing against the received interpretation, according to which essences are classificatory, Witt maintains that a substances essence is what causes it to exist. In addition, Substance and Essence in Aristotle challenges the orthodox view that Aristotelian essences are species-essences, defending instead the controversial position that they are individual essences. Finally, Witt compares Aristotelian essentialism to contemporary essentialist theories, focusing in particular on Kripkes work. She concludes that fundamental differences between Aristotelian and contemporary essentialist theories highlight important features of Aristotles theory and the philosophical problems and milieu that engendered it.