Nationalism is an infantile disease. It is the measles of mankind.

The ancients knew something, which we seem to have forgotten.

If you feed your mind as often as you feed your stomach, then you'll never have to worry about feeding your stomach or a roof over your head or clothes on your back.

As long as I have any choice in the matter, I shall live only in a country where civil liberty, tolerance and equality of all citizens before the law prevail.

Conscious man, to be sure, has at all times been keenly aware that life is an adventure, that life must, forever, be wrested from death.

The only rational way of educating is to be an example. If one can't help it, a warning example.

What distinguishes the language of science from language as we ordinarily understand the word? ... What science strives for is an utmost acuteness and clarity of concepts as regards their mutual relation and their correspondence to sensory data.