It is here [in mathematics] that the artist has the fullest scope of his imagination.

There is held to be no surer test of civilization than the increase per head of the consumption of alcohol and tobacco. Yet alcohol and tobacco are recognizable poisons, so that their consumption has only to be carried far enough to destroy civilization altogether.

The sexual regions constitute a particularly vulnerable spot, and remain so even in man, and the need for their protection which thus exists conflicts with the prominent display required for sexual allurement. This end is far more effectively attained, with greater advantage and less disadvantage, by concentrating the chief ensigns of sexual attractiveness on the upper and more conspicuous parts of the body. This method is well-nigh universal among animals as well as in man.

At the present day the crude theory of the sexual impulse held on one side, and the ignorant rejection of theory altogether on the other side, are beginning to be seen as both alike unjustified.

What we call progress is the exchange of one nuisance for another nuisance.

All the art of living lies in a fine mingling of letting go and holding on.

Beauty is the child of love.