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.

We are so constituted that we can gain intense pleasure only from the contrast, and only very little from the condition itself.

The Mosaic religion had been a Father religion; Christianity became a Son religion. The old God, the Father, took second place; Christ, the Son, stood in His stead, just as in those dark times every son had longed to do.

No one who has seen a baby sinking back satiated from the breast and falling asleep with flushed cheeks and a blissful smile can escape the reflection that this picture persists as a prototype of the expression of sexual satisfaction in later life.

Religion is comparable to a childhood neurosis.

I have found little 'good' about human beings. In my experience, most of them are trash.

Thinking is an experimental dealing with small quantities of energy, just as a general moves miniature figures over a map before setting his troops in action.