Naturalism aimed at giving the primitive wishes full play but failed because these wishes are too primitive, too infantile, too inconsistent with themselves to be satisfied even by the greatest license.

Hunger and sex still dominate the primitive mammalian side of human existence, but at the present time it looks as if humanity were within sight of their satisfaction. Permanent plenty, no longer a Utopian dream, awaits the arrival of permanent peace.

The beauty of life is, therefore, geometrical beauty of a type that Plato would have much appreciated.

It is characteristic of science that the full explanations are often seized in their essence by the percipient scientist long in advance of any possible proof.

The psychology of a complex mind must differ almost as much from that of a simple, mechanized mind as its psychology would from ours; because something that must underlie and perhaps be even greater than sex is involved.

The present aristocracy of western culture, at the very moment when it most clearly dominates the world, is being imitated rapidly and successfully in every eastern country.

The question of the origin of life is essentially speculative. We have to construct, by straightforward thinking on the basis of very few factual observations, a plausible and self-consistent picture of a process which must have occurred before any of the forms which are known to us in the fossil record could have existed.