Mary-Louise Gill

The fourfold division in Plato’s _Philebus_ develops machinery to decide the contest between pleasure and reason for second place after the mixture in the debate about the good life. The machinery consists of the limit, the unlimited, the mixture of limit and unlimited, and cause of the mixture. Plato’s Socrates collects instances of the unlimited and mixture to determine their unified nature and marks off the cause from the other three kinds and argues for its priority. We gain understanding of the limit by considering its operation in relation to the other three kinds. The limit is responsible for external and internal boundaries in an unlimited, bringing definiteness either by marking something off from things outside it or by providing internal structure. Chapter 5 argues that one key function of the limit is omitted in the fourfold division: guaranteeing the goodness of a mixture.

Chapter 6 examines the statesman, who turns up at the tip of a single branch of a divisional tree but is puzzling because he has many rivals who profess that they, too, look after humans who live in a city. To mark off the statesman from his rivals, Plato’s Stranger introduces a new model — weaving — and a new divisional technique, division by limbs. The _Statesman_ is important to the larger project about the philosopher in showing that, in some cases, defining the object of an art may take the inquirers only part way toward their destination. To mark off the statesman from others who work in the same domain, the inquirer must also consider the statesman’s perspective on the object, his manner of dealing with it, and the good he attempts to achieve.

Chapter 7 reconstructs Plato’s portrait of the philosopher, starting with the problematic fourth step in the dialectical exercise in the _Sophist_, which undermines the constructive proposal about being in the Battle of the Gods and Giants; and then turning to the analysis of dialectic (with the aid of the _Philebus_). The chapter argues that the fourth step rests on Socrates’ mistaken assumption in the _Parmenides_ that forms cannot partake of their own opposite. To solve the puzzle about being, one must accept that change and rest partake of each other. With that correction, one can define being in terms of rest and change, and the philosopher as having expertise directed toward being. The major hurdle has been crossed, but the philosopher still has competitors who vie for the title “philosopher.” The chapter ends by appealing to further criteria in the _Statesman_ to mark off the philosopher from his closest rivals.

Using an angler as model, the _Sophist_ — the focus of Chapter 5 — presents six divisions and definitions of the sophist and thereby reveals that the sophist is puzzling because he appears in so many different ways, encouraging people to think he knows things he does not know. To unmask the sophist in the final division, the inquirers need to make sense of appearances and untangle the problems of not-being (interpreted as difference), negation, and false statement, the major weapon of the sophist, who is finally identified as the imitator of the wise man. This chapter analyzes sameness and being using the model of difference and argues that the sophist must ultimately be ousted from the genus expertise, since he is ignorant of what he is imitating.

Chapter 4 argues that the _Theaetetus_ seeks to define knowledge as expertise, the genus to be divided in the search for the sophist, statesman, and philosopher. The genus is defined by analysis into its elementary parts according to the second of three notions of account (_logos_) in the last part of the dialogue. The _Theaetetus_ ends in apparent failure, having tried to identify knowledge with perception, true judgment, or true judgment with an account, but a constructive solution is permitted by conceiving of knowledge as expertise, defined as a combination of those components. A problem remains about how to distinguish knowledge from belief, and this chapter argues that Plato provides the resources to distinguish them: the difference turns on the aspects of the object perceived and the account that grounds a correct matching of the object perceived to the perceiver’s mental impression of it.

Chapter 3 argues that a second round of the philosophical exercise concerns the form of being, the philosopher’s object, and spans parts of the _Theaetetus_ and _Sophist_. Plato’s Socrates presents two opposed positions, the Heraclitean view that being is changing, and the Parmenidean view that being is at rest. After both positions have been refuted, Plato’s Stranger seeks to reconcile them in the Battle of the Gods and Giants in the _Sophist_ and defines being as the capacity to remain the same (rest) and to act on or be affected by other things (change). No sooner does he find a middle way than he undermines it in the fourth step of the dialectical pattern, rendering being totally mysterious. This book contends that the audience must find its way back to the constructive solution at step three to locate Plato’s philosopher.

The second part of the _Parmenides_ presents a dialectical exercise about the form of oneness, the first round of a larger dialectical program. Chapter 2 argues that the exercise develops a single argument which challenges the student to find a way to save the positive hypothesis that the one is. The exercise shows that the youthful Socrates in the first part of the dialogue was wrong to suppose that forms cannot partake of other forms. In some cases a form partakes of its own opposite — in particular, the one is many, as well as one. A form has its own character in virtue of itself (_auto kath’ hauto_) and has features other than its own through partaking of other forms (_pros alla:_ in relation to other things). Part II of the _Parmenides_ also highlights the problem of being, subject of the second round of the dialectical exercise.

This chapter sets out the theory of forms defended in the _Parmenides_ and spelled out in more detail in the _Phaedo_ and the objections leveled against forms to determine how the theory can be revised and preserved. Among the main problems discussed are participation (initially the relation between sensible particulars and forms), self-predication (the form of F-ness is itself F), forms as causes, and the question whether forms are separate (exist apart) from the things whose features they are invoked to explain or are immanent in them. The chapter argues that many problems stem from the separation of forms. Later chapters will show that the dialogues in the series _Theaetetus-Sophist-Statesman_ treat forms as immanent but keep much of the rest of the theory intact.

The Introduction asks why the final dialogue in the series _Theaetetus-Sophist-Statesman-Philosopher_ is missing and considers the portrait of the philosopher it would have contained. Plato left the final dialogue unwritten to challenge his audience to work out its contents using the resources of the _Parmenides_ and the existing series. The portrait includes two main components: first, the philosopher’s object — being — the subject-matter he studies; and second, the philosopher’s knowledge, his special expertise in dealing with that object. A third topic treated in the Introduction is the philosopher’s product, his discourse, and in particular Plato’s discourse. The Introduction discusses Plato’s written dialogues and their purpose of training students through practice solving philosophical problems. The Introduction ends by setting out the dialectical pattern used to bring the philosopher into view, a pattern matching that in the philosophical exercise in the second part of the _Parmenides._.

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 inMetaphysics 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 byte 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.

The concept of self-motion is not only fundamental in Aristotle's argument for the Prime Mover and in ancient and medieval theories of nature, but it is also central to many theories of human agency and moral responsibility. In this collection of mostly new essays, scholars of classical, Hellenistic, medieval, and early modern philosophy and science explore the question of whether or not there are such things as self-movers, and if so, what their self-motion consists in. They trace the development of the concept of self-motion from its formulation in Aristotle's metaphysics, cosmology, and philosophy of nature through two millennia of philosophical, religious, and scientific thought. This volume contains "Self-Movers" (David Furley), "Aristotle on Self-Motion" (Mary Louise Gill), "Aristotle on Perception, Appetition, and Self-Motion" (Cynthia Freeland), "Self-Movement and External Causation" (Susan Sauvé Meyer), "Aristotle on the Mind's Self-Motion" (Michael Wedin), "Mind and Motion in Aristotle" (Christopher Shields), "Aristotle's Prime Mover" (Aryeh Kosman), "The Transcendence of the Prime Mover" (Lindsay Judson), "Self-Motion in Stoic Philosophy" (David Hahm), "Duns Scotus on the Reality of Self-Change" (Peter King), "Ockham, Self-Motion, and the Will" (Calvin Normore), and "Natural Motion and Its Causes: Newton on the 'Vis Insita' of Bodies" (J. E. McGuire). Originally published in 1994. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

_A Companion to Ancient Philosophy_ provides a comprehensive and current overview of the history of ancient Greek and Roman philosophy from its origins until late antiquity. Comprises an extensive collection of original essays, featuring contributions from both rising stars and senior scholars of ancient philosophy Integrates analytic and continental traditions Explores the development of various disciplines, such as mathematics, logic, grammar, physics, and medicine, in relation to ancient philosophy Includes an illuminating introduction, bibliography, chronology, maps and an index.

_A Companion to Ancient Philosophy_ provides a comprehensive and current overview of the history of ancient Greek and Roman philosophy from its origins until late antiquity. Comprises an extensive collection of original essays, featuring contributions from both rising stars and senior scholars of ancient philosophy Integrates analytic and continental traditions Explores the development of various disciplines, such as mathematics, logic, grammar, physics, and medicine, in relation to ancient philosophy Includes an illuminating introduction, bibliography, chronology, maps and an index.

Platonic forms explain certain features of perceptible things and equip us to know them. This paper examines three passages: the Greatest Difficulty in the Parmenides shows that Socrates’ failure to explain participation, the relation between sensible things and forms, renders forms unknowable to us. The Battle of Gods and Giants in the Sophist treats forms as immutable, but their immutability apparently rules out their intelligibility. The Stranger offers a path forward by defining being as power, a solution then undermined in the Aporia about Being, which reveals that the form of being is neither immutable nor intelligible. This paper shows where the Aporia goes wrong and opens a way back to the constructive proposal in the Battle of Gods and Giants. The paper finally considers how forms are affected in being known and gestures toward Plato’s solution to the problem of participation.

Metaphysics Θ treats potentiality (δύναμις) and actuality (ἐνέργεια), and many scholars think that Aristotle broaches these topics once he has answered his main questions in Ζ and Η. In Ζ he asked, what is primary being? After arguing in Ζ.1 that substance (οὐσία) is primary being—a being existentially, logically, and epistemologically prior to quantities and qualities and other categorial beings—he devotes the rest of the book to οὐσία itself, investigating what it is, to decide what entities count as primary substances. I differ from the leading interpretative consensus that ΖΗ adequately answer the questions about primary substance, and contend instead that Metaphysics Θ continues the same investigation as ΖΗ and, using δύναμις and ἐνέργεια as tools, arrives at a striking new conception of hylomorphism, different from that in ΖΗ, which enables Aristotle to defend the substantial primacy of living organisms consisting of matter and form.

This volume presents fourteen essays by leading figures in the fields of ancient philosophy and contemporary metaphysics, discussing Aristotle's theory of the unity and identity of substances, a topic that remains at the center 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 are: What does Aristotle mean by "potentiality" and "actuality?" How do these concepts explicate matter and form, and how are they related to the actuality of a substance? What is the role of actuality in accounting for the unity and identity of substance? 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 give answers to central problems in Aristotle's metaphysics, and also to stimulate further investigation of the problems defined and the controversies embodied.

Aristotle's metaphysics has stimulated intense renewed debate in the past twenty years. Much of the discussion has focused on Metaphysics Z, Aristotle's fascinating and difficult investigation of substance , and to a lesser extent on H and Θ. The place of the central books within the larger project of First Philosophy in the Metaphysics has engaged scholars since antiquity, and that relationship has also been reexamined. In addition, scholars have been exploring the Metaphysics from various broader perspectives—first, in relation to Aristotle's natural philosophy, his physics, biology, and psychology, and to the Organon, his so-called "logical" works, which include the Categories, Topics, and Posterior Analytics; and second, in relation to the broader philosophical tradition, both Plato before him and the ancient commentary tradition in late antiquity