When the Special Theory of Relativity began to germinate in me, I was visited by all sorts of nervous conflicts... I used to go away for weeks in a state of confusion.

I am also convinced that one gains the purest joy from spirited things only when they are not tied in with earning one's livelihood.

On the other hand, the concept owes its meaning and its justification exclusively to the totality of the sense impressions which we associate with it.

[O]nly if every individual strives for truth can humanity attain a happier future; the atavisms in each of us that stand in the way of a friendlier destiny can only thus be rendered ineffective.

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.

When I was a fairly precocious young man I became thoroughly impressed with the futility of the hopes and strivings that chase most men restlessly through life. Moreover, I soon discovered the cruelty of that chase, which in those years was much more carefully covered up by hypocrisy and glittering words than is the case today. By the mere existence of his stomach everyone was condemned to participate in that chase. The stomach might well be satisfied by such participation, but not man insofar as he is a thinking and feeling being.

Make everything as simple as possible, but not simpler.