The mirror is a worthless invention. The only way to truly see yourself is in the reflection of someone else's eyes.

I have wanted to kill myself a hundred times, but somehow I am still in love with life. This ridiculous weakness is perhaps one of our more stupid melancholy propensities, for is there anything more stupid than to be eager to go on carrying a burden which one would gladly throw away, to loathe one’s very being and yet to hold it fast, to fondle the snake that devours us until it has eaten our hearts away?

When he to whom one speaks does not understand, and he who speaks himself does not understand, that is Metaphysics.

Descartes constructed as noble a road of science, from the point at which he found geometry to that to which he carried it, as Newton himself did after him. ... He carried this spirit of geometry and invention into optics, which under him became a completely new art.

Among the illusions which have invested our civilization is an absolute belief that the solutions to our problems must be a more determined application of rationally organized expertise... The reality is that our problems are largely the product of that application.

Man is free at the instant he wants to be.

Work spares us from three evils: boredom, vice, and need.