Many a man will have the courage to die gallantly, but will not have the courage to say, or even to think, that the cause for which he is asked to die is an unworthy one.

Human life, its growth, its hopes, fears, loves, et cetera, are the result of accidents

Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.

In any closet, you can find it, if it is too small, or out of style, or there is just one of it where there should be two

A life which goes excessively against natural impulse is... likely to involve effects of strain that may be quite as bad as indulgence in forbidden impulses would have been. People who live a life which is unnatural beyond a point are likely to be filled with envy, malice and uncharitableness.

All serious innovation is only rendered possible by some accident enabling unpopular persons to survive.

Fear is the parent of cruelty, and therefore it is no wonder if cruelty and religion have gone hand-in-hand. It is because fear is at the basis of those two things. In this world we can now begin a little to understand things, and a little to master them by the help of science, which has forced its way step by step against the Christian religion, against the churches, and against the opposition of all the old precepts.