Theory of Knowledge

In a vat, a brain floating in liquid is connected to a computer.  A thought bubble above the brain reads "I'm walking outside in the sun!!"

Hilary Putnam's "Brain in a Vat" thought experiment is a modern version of Descartes' argument of an evil demon feeding false information to the senses. (This image is in the public domain. Source: Was a bee.)


MIT Course Number


As Taught In

Spring 2014



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Course Features

Course Description

This course is an introduction to epistemology: the theory of knowledge. We will focus on skepticism—that is, the thesis that we know nothing at all—and we will survey a range of skeptical arguments and responses to skepticism.

Other OCW Versions

Archived versions: Question_avt logo

Smithies, Declan. 24.211 Theory of Knowledge, Spring 2014. (MIT OpenCourseWare: Massachusetts Institute of Technology), (Accessed). License: Creative Commons BY-NC-SA

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