Dowling College PHL003

Notes on Descartes' Epistemology

He doubts everything (or nearly everything). The existence of the physical world and his own physical body, the truths of arithmetic and geometry.

This is not a practical doubt, it is theoretical. There is nothing I can do to resolve the doubt.

He takes them seriously enough so that they affect his philosophy.

Descartes is only doubting in order to find truth.

Eventually he does find certainty. When he is doubting, he knows he is doubting. He knows he is thinking. So he knows that he exists. Whenever he is thinking and doubting, he is certain of his existence.

In the rest of his Meditations, he builds on this certainty, regains all of the beliefs he previously doubted. He comes again to be certain of mathematical truth, of the existence of his body, and the nature of the world. His doubting is just temporary, it was just a stage in his meditation.

20^th century work on this topic is Ludwig Wittgenstein: On Certainty.

Bouwsma says that a complete deception is not a deception at all. The constructed world is exactly the same as the real world, and so it is real.

So it gets to the issue of what is reality? It preoccupied Locke, Hume, Berkeley, Immanuel Kant.

Twentieth century philosophers very preoccupied by the relation between language and reality.