It is only a man's own fundamental thoughts that have truth and life in them. For it is these that he really and completely understands. To read the thoughts of others is like taking the remains of someone else's meal, like putting on the discarded clothes of a stranger.

Philosophy ... is a science, and as such has no articles of faith; accordingly, in it nothing can be assumed as existing except what is either positively given empirically, or demonstrated through indubitable conclusions.

The bad thing about all religions is that, instead of being able to confess their allegorical nature, they have to conceal it.

The brain may be regarded as a kind of parasite of the organism, a pensioner, as it were, who dwells with the body.

The man who sees two or three generations is like one who sits in the conjuror's booth at a fair, and sees the same tricks two or three times. They are meant to be seen only once.

The little honesty that exists among authors is discernible in the unconscionable way they misquote from the writings of others.

How is it possible that suffering that is neither my own nor of my concern should immediately affect me as though it were my own, and with such force that is moves me to action?