Man could escape danger only by renouncing adventure, by abandoning that which has given to the human condition its unique character and genius among the rest of living things.

... each type of civilization has had diseases peculiar to it and at each period the various social groups in any community also have differed in this regard.

Human destiny is bound to remain a gamble, because at some unpredictable time and in some unforeseeable manner nature will strike back.

Man not only survives and functions in his environment, he shapes it and he is shaped by it.

It is possible to analyze the biological and social influences that make each human being unique, unprecedented, and unrepeatable, but this analysis does not explain how and why each feels different from all other human beings.

Think globally, act locally": "Our salvation depends upon our ability to create a religion of nature.

Man shapes himself through decisions that shape his environment.