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Plato's 'Theaetetus'

What is knowledge? Plato's 'Theaetetus' is the first systematic exploration of this question, and the main themes of this dialogue continue to be debated in philosophy to this day. In the course, we will read and discuss the text in full.

The dialogue ‘Theaetetus’ is Plato’s (427–347 BCE) most detailed attempt to define knowledge. It is truly ground breaking. In other dialogues, Plato has Socrates enquire whether we can know courage, justice, virtue, and so on; in the ‘Theaetetus’ he asks whether we can know knowledge itself. Insofar as this question remains a cornerstone of philosophy, Plato’s themes are ours too: and since his exploration is accessible to a modern audience, its main issues and considerations are recognisable from today’s perspective. Even though the text is not easy, it is both a fascinating introduction to the theory of knowledge (or epistemology) suitable to beginners like Theaetetus himself, and it raises interesting questions about Plato and his philosophy. Puzzlingly, for instance, the ‘Theaetetus’ is not consistent with his discussions of knowledge elsewhere. In the course, we will read the entire dialogue and think it through in discussion; with occasional views to other works, such as the ‘Meno’ and ‘Phaedo’.

Date created:

2017-04-24 10:09
Course type: 

Resources for this course

Displaying 1 - 15 of 15
Type Resource Description People Full details
Document Plato: Influences, Context, Works

Background information about six major influences that inform Plato's philosophy; with additional information about his life and works.

Peter Wyss view
Document Theaetetus 142-160 (Coursework 1)

A sheet with leading questions and background information for reading Theaetetus up to 160; information about coursework (credit) options.

Peter Wyss view
Document Introducing Plato

The slides from our first meeting.

Peter Wyss view
Link Plato on Knowledge in the Theaetetus

An excellent entry in the Stanford Encyclopedia of Philosophy by S.-G. Chappell.

Document Setting the Stage

Notes for Theaetetus 145–151: initial assumptions, kinds of knowledge, midwifery, and elenchus.

Peter Wyss view
Document Notes on the First Definition

Remarks on Theaetetus' first definition, Protagoras and Heraclitus (Tht 151-160).

Peter Wyss view
Document A Map of Theaetetus

A rough and ready overview of the dialogue.

Peter Wyss view
Document Perception (153d-154a, 156a-157c)

Clarificatory notes on the noted passages, in relation to our discussion in the third meeting.

Peter Wyss view
Document Theaetetus 161–186 (Coursework 2)

Leading questions and background information for reading up to Theaetetus 186 (i.e. the refutation of D1).

Peter Wyss view
Link Parmenides

Encyclopedia entry about Parmenides (see Theaetetus 180e, 183e) by J. Palmer.

Link Heraclitus

Encyclopedia entry about Heraclitus by D. W. Graham.

Document Is Socrates' Irony Ironical?

An attempt to clarify irony and eironeia.

Peter Wyss view
Document Five (More) Arguments Against D1

Sketches of the more sustantial arguments against D1 between 170 and 186.

Peter Wyss view
Document From D1 to D2

Two pages of background information for Theaetetus 186–191, including a worksheet for the first two puzzles about false judging.

Peter Wyss view
Document Theaetetus 187-210 (Coursework 3)

Sheet with a few leading questions and background information for the final part of the dialogue.

Peter Wyss view