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.

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

Any attempt to shape the world and modify human personality in order to create a self-chosen pattern of life involves many unknown consequences. Human destiny is bound to remain a gamble, because at some unpredictable time and in some unforeseeable manner nature will strike back. The multiplicity of determinants which affect biological systems limits the power of the experimental method to predict their trends and behavior.

Eradication of microbial disease is a will-o'-the-wisp; pursuing it leads into a morass of hazy biological concepts and half truths.

Man will survive as a species for one reason: He can adapt to the destructive effects of our power-intoxicated technology and of our ungoverned population growth, to the dirt, pollution and noise of a New York or Tokyo. And that is the tragedy. It is not man the ecological crisis threatens to destroy but the quality of human life.

Human life is now molded to a large extent by the changes that man has brought about in his external environment and by his attempts at controlling body and soul.

... men as a rule are more preoccupied with the dangers that threaten their life than interested in the biological forces on which they depend for a constructive existence.