The luxury to disparage freedom is the privilege of those who already possess it.

Thought is subversive and revolutionary, destructive and terrible, Thought is merciless to privilege, established institutions, and comfortable habit. Thought is great and swift and free.

Do not fear to be eccentric in opinion, for every opinion now accepted was once eccentric.

I do not pretend to be able to prove that there is no God. I equally cannot prove that Satan is a fiction. The Christian god may exist; so may the gods of Olympus, or of ancient Egypt, or of Babylon. But no one of these hypotheses is more probable than any other: they lie outside the region of even probable knowledge, and therefore there is no reason to consider any of them.

Every great idea starts out as a blasphemy.

The scientific attitude of mind involves a sweeping away of all other desires in the interests of the desire to know-it involves suppression of hopes and fears, loves and hates, and the whole subjective emotional life, until we become subdued to the material, able to see it frankly, without preconceptions, without bias, without any wish except to see it as it is, and without any belief that what it is must be determined by some relation, positive or negative, to what we should like it to be, or to what we can easily imagine it to be.

Animal rights, taken to their logical conclusion, mean votes for oysters.