You asked me where I generally lived. In my workshop [i.e. in his study] in the mornings and always in the library in the evening. Books are companions even if you don’t open them.

Scientific, like spiritual truth, has ever from the beginning been descending from heaven to man.

The Duke of Wellington brought to the post of first minister immortal fame,-a quality of success which would almost seem to include all others.

You know, all is development. The principle is perpetually going on. First, there was nothing, then there was something; then-I forget the next-I think there were shells, then fishes; then we came-let me see-did we come next? Never mind that; we came at last. And at the next change there will be something very superior to us-something with wings. Ah! That's it: we were fishes, and I believe we shall be crows.

Circumstances are beyond human control, but our conduct is in our own power.

Read no history: nothing but biography, for that is life without theory.

One should conquer the world, not to enthrone a man, but an idea; for ideas exist forever.