I ... having filled my life with the spiritual blessings Christianity gave me, brimful of these blessings and living by them, I, like a child, not understanding them, destroy them -- that is, I wish to destroy that by which I live.

Men are like rivers: the water is the same in each, and alike in all; but every river is narrow here, is more rapid there, here slower, there broader, now clear, now cold, now dull, now warm. It is the same with men. Every man carries in himself the germs of every human quality, and sometimes one manifests itself, sometimes another, and the man often becomes unlike himself, while still remaining the same man.

It is easier to produce ten volumes of philosophical writings than to put one principle into practice.

What I think about vivisection is that if people admit that they have the right to take or endanger the life of living beings for the benefit of many, there will be no limit to their cruelty.