Human life implies adventure, and there is no adventure without struggles and dangers.

The word "wilderness" occurs approximately three hundred times in the Bible, and all its meanings are derogatory.

Nature always strikes back. It takes all the running we can do to remain in the same place.

Biologically, man is still the great amateur of the animal kingdom; he is unique in his lack of anatomical and physiological specialization.

There is a demon in technology. It was put there by man and man will have to exorcise it before technological civilization can achieve the eighteenth-century ideal of humane civilized 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.

The mechanisms of vis medicatrix naturæ—the most healing power of nature—are so effective that most diseases are self-terminating.