Sometimes I think it is a great mistake to have matter that can think and feel. It complains so. By the same token, though, I suppose that boulders and mountains and moons could be accused of being a little too phlegmatic.

If I should ever die, God forbid, I hope you will say, 'Kurt is up in heaven now.' That's my favorite joke.

This world is not a vale of sorrows if you will recognize discriminatingly what is truly excellent in it; and if you will avail yourself of it for mutual happiness and well-being. Therefore, let us explain as often as possible, and particularly at the departure of life, that we base our faith on firm foundations, on Truth for putting into action our ideas which do not depend on fables and ideas which Science has long ago proven to be false.

He had the air of a spy in a melodrama, missing nothing, liking nothing, looking forward to the great day when everything would be turned upside down.

Is there nothing I have done which will outlive me, other than the opprobrium of my first wife and sons and grandchildren? Do I care? Doesn't everybody? Poor me. Poor practically everybody, with so little durable good to leave behind!

Earthlings went on being friendly, when they should have been thinking instead.

The arts are not a way to make a living.