The whole thing [religion] is so patently infantile, so foreign to reality, that to anyone with a friendly attitude to humanity it is painful to think that the great majority of mortals will never be able to rise above this view of life.

There is to my mind no doubt that the concept of beautiful had its roots in sexual excitation and that its original meaning was sexually stimulating.

It is unreasonable to expect science to produce a system of ethics-ethics are a kind of highway code for traffic among mankind-and the fact that in physics atoms which were yesterday assumed to be square are now assumed to be round is exploited with unjustified tendentiousness by all who are hungry for faith; so long as physics extends our dominion over nature, these changes ought to be a matter of complete indifference to you.

I do not doubt that it would be easier for fate to take away your suffering than it would for me. But you will see for yourself that much has been gained if we succeed in turning your hysterical misery into common unhappiness.

Long ago man formed an ideal conception of omnipotence and omniscience which he embodied in his gods. Whatever seemed unattainable to his desires - or forbidden to him - he attributed to these gods... Now he has himself approached very near to realizing this ideal, he has nearly become a god himself.

The first requisite of civilization, therefore, is that of justice — that is, the assurance that a law once made will not be broken in favour of an individual. This implies nothing as to the ethical value of such a law.

I consider it a good rule for letter-writing to leave unmentioned what the recipient already knows, and instead tell him something new.