To do nothing at all is the most difficult thing in the world, the most difficult and the most intellectual.

All love is true, but not all truth ... is love?

You and I will always be friends." "Yet you poisoned me with a book once. I should not forgive that.

If one tells the truth, one is sure, sooner or later, to be found out.

Science can never grapple with the irrational. That is why it has no future before it, in this world.

In England, an inventor is regarded almost as a crazy man, and in too many instances invention ends in disappointment and poverty. In America, an inventor is honoured, help is forthcoming, and the exercise of ingenuity, the application of science to the work of man, is there the shortest road to wealth.

Circumstances should never alter principles!