David Sedley

This lecture was designed as an introduction to Plato's theory of Forms. Reference is made to key passages of Plato's dialogues, but no guidance on further reading is offered, and numerous controversies about the theory's interpretation are left in the background. An initial sketch of the theory's origins in the inquiries of Plato's teacher Socrates is followed by an explanation of the Forms’ primary characteristic, Plato's metaphysical separation of them from the sensible world. Other aspects discussed include the Forms’ metaphysical relation to sensible particulars, their ‘self-predication’, and the range of items that have Forms. Finally, the envisaged structure of the world of Forms is illustrated by a look at Plato's famous Cave simile.

This paper examines Plato's ideas on cause-effect relations in the "Phaedo." It maintains that he sees causes as things (not events, states of affairs or the like), with any information as to how that thing brings about the effect relegated to a strictly secondary status. This is argued to make good sense, so long as we recognise that aition means the "thing responsible" and exploit legal analogies in order to understand what this amounts to. Furthermore, provided that we do not pre-suppose that we already know what can and what cannot count as a cause, Plato proves to have an attractive case for his principle that all causation is a matter of like causing like. Once we appreciate this, we are a little closer to understanding his more idiosyncratic principle, which although puzzling is ubiquitous in his writings and often invoked as a premise in key arguments, that opposites cannot cause opposites. The last part of the paper turns to formal causes, defending Plato's advocacy of them, and examining their role in the "Parmenides'" Third Man Argument. The main proposal is that Plato's conception of Forms as causes opens the door to a better version of that argument's "Non-identity" premise than those currently available

Plato's Meno and Phaedo are two of the most important works of ancient western philosophy and continue to be studied around the world. The Meno is a seminal work of epistemology. The Phaedo is a key source for Platonic metaphysics and for Plato's conception of the human soul. Together they illustrate the birth of Platonic philosophy from Plato's reflections on Socrates' life and doctrines. This edition offers new and accessible translations of both works, together with a thorough introduction that explains the arguments of the two dialogues and their place in Plato's thought.

This paper is a critical re-examination of the argument in Plato's "Phaedo" for the thesis that all learning is recollection of prenatal knowledge. Plato's speaker Socrates concentrates on the case of 'equal sticks and stones', viewed as striving without complete success to resemble a Form, the Equal itself. The paper argues that (a) this is a rather special case, focused on geometry; (b) Plato is at pains to emphasize that the Form-particular relation need not be one of resemblance at all, a concession which he insists would not, if made, damage his theory of recollection; (c) even if resemblance is assumed to be the correct account of that relationship, the 'striving to be like' gloss is not an integral component of Plato's metaphysics.

Plato's Theaetetus is an acknowledged masterpiece, and among the most influential texts in the history of epistemology. Since antiquity it has been debated whether this dialogue was written by Plato to support his familiar metaphysical doctrines, or represents a self-distancing from these. David Sedley's book offers a via media, founded on a radical separation of the author, Plato, from his main speaker, Socrates. The dialogue, it is argued, is addressed to readers familiar with Plato's mature doctrines, and sets out to show how these doctrines, far from being an abandonment of his Socratic heritage, are its natural outcome. The Socrates portrayed here is the same Socrates as already portrayed in Plato's early dialogues. While not a Platonist, he is exhibited - to put it in terms of an image made famous by this dialogue - as having been Platonism's midwife. In a comprehensive rereading of the text, Sedley tracks the ways in which Socrates is shown unwittingly preparing the ground for Plato's mature doctrines, and reinterprets the dialogue's individual arguments from this perspective. The book is addressed to all readers interested in Plato, and does not require knowledge of Greek.

The world is configured in ways that seem systematically hospitable to life forms, especially the human race. Is this the outcome of divine planning or simply of the laws of physics? Ancient Greeks and Romans famously disagreed on whether the cosmos was the product of design or accident. In this book, David Sedley examines this question and illuminates new historical perspectives on the pantheon of thinkers who laid the foundations of Western philosophy and science. Versions of what we call the "creationist" option were widely favored by the major thinkers of classical antiquity, including Plato, whose ideas on the subject prepared the ground for Aristotle's celebrated teleology. But Aristotle aligned himself with the anti-creationist lobby, whose most militant members—the atomists—sought to show how a world just like ours would form inevitably by sheer accident, given only the infinity of space and matter. This stimulating study explores seven major thinkers and philosophical movements enmeshed in the debate: Anaxagoras, Empedocles, Socrates, Plato, the atomists, Aristotle, and the Stoics.

Presocratic atomism was one of the most influential of the early theories: both Plato and Aristotle thought of it as a major competing theory, and it was an important source for post-Aristotelian Hellenistic theories. It has been commonplace that the atomism developed first by Leucippus of Abdera and then by Democritus of Abdera was a reaction to the Eleatic arguments of Zeno and Melissus, but the details of that influence have sometimes seemed rather hazy. This article brings them into sharper focus. This article considers the Eleatic foundations of atomism, especially the question of the importance of Zeno and Melissus for Democritus. By concentrating on some of the less-studied aspects of atomism and especially of the development of the concept of the unlimited into the notion of the infinite, it furthers the understanding of not only the development of early atomism but also the Eleatics Zeno and Melissus.

How does God think? How, ideally, does a human mind function? Must a gap remain between these two paradigms of rationality? Such questions exercised the greatest ancient philosophers, including those featured in this book: Socrates, Plato, Aristotle, the Stoics and Plotinus. This volume encompasses a series of studies by leading scholars, revisiting key moments of ancient philosophy and highlighting the theme of human and divine rationality in both moral and cognitive psychology. It is a tribute to Professor A. A. Long, and reflects multiple themes of his own work.

Le chapitre 4 du premier livre des Mémorables de Xénophon était quasiment un texte canonique pour la théologie des premiers stoïciens : il contient la première version de « la preuve par la providence » (the Argument from Design) et constitue un témoignage capital et négligé concernant la théologie de Socrate. Les idées qui y sont exposées ne dérivent en effet pas de Diogène d'Apollonie, dont le rôle dans l'histoire de la pensée téléologique a été largement surestimé. Je défends la thèse que le texte du Contre les savants IX, 88-110 de Sextus Empiricus constitue un témoignage unique qui permet de comprendre comment les premiers stoïciens se sont efforcés d'extraire une preuve rigoureuse de l'existence de dieu du chapitre de Xénophon ainsi que du Timée de Platon (29b-30b), et comment ils ont ensuite corrigé leurs syllogismes pour les soustraire aux réfutations parodiques (parabolai) d'Alexinus. On peut ainsi observer la manière dont les stoïciens ont forgé leurs armes théologiques à partir de la tradition dont ils prétendaient être les héritiers.