Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders. Do not believe in traditions because they have been handed down for many generations. But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it.

The philosophers have only interpreted the world, in various ways: the point, however, is to change it.

Greek philosophy seems to have met with something with which a good tragedy is not supposed to meet, namely, a dull ending.

Philosophy stands in the same relation to the study of the actual world as masturbation to sexual love.

The power of philosophy floats through my head.. light like a feather, heavy as lead.

Ordinary people seem not to realize that those who really apply themselves in the right way to philosophy are directly and of their own accord preparing themselves for dying and death.