Religion is based ... mainly upon fear ... fear of the mysterious, fear of defeat, fear of death. Fear is the parent of cruelty, and therefore it is no wonder if cruelty and religion have gone hand in hand. My own view on religion is that of Lucretius. I regard it as a disease born of fear and as a source of untold misery to the human race.

Morally, a philosopher who uses his professional competence for anything except a disinterested search for truth is guilty of a kind of treachery.

Mankind has become so much one family that we cannot insure our own prosperity except by insuring that of everyone else.

I think we ought always to entertain our opinions with some measure of doubt. I shouldn't wish people dogmatically to believe any philosophy, not even mine.

Philosophy, if it cannot answer so many questions as we could wish, has at least the power of asking questions which increase the interest of the world, and show the strangeness and wonder lying just below the surface even in the commonest things of daily life.

Whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find, on examination, that your belief is going beyond what the evidence warrants.

All the labor of all the ages, all the devotion, all the inspiration, all the noonday brightness of human genius are destined to extinction. So now, my friends, if that is true, and it is true, what is the point?