Our Knowledge of the External World

Plato's deepest attempt to define knowledge. Socrates tests whether it is perception, true belief, or true belief with an account, and the problems he finds still drive the theory of knowledge today.

Plato

Can we learn something we don't already know? Socrates guides a young slave through a geometry proof to argue that learning is recollection, the first theory of knowledge prior to experience.

Plato

Kant's map of what reason can and cannot know. It explains how space, time and the categories shape all experience, and why metaphysics overreaches when it goes beyond them.

Immanuel Kant

Russell's short classic on what we can know for certain, from the existence of matter to knowledge by acquaintance and by description. Still the friendliest entry point to the theory of knowledge.

Bertrand Russell

Prichard's classic 1909 commentary walks through the Critique of Pure Reason argument by argument, from space and time to the refutation of idealism. Best read side by side with Kant.

H. A. Prichard