Custom has furnished the only basis which ethics have ever had.

Science has always promised two things not necessarily related; an increase first in our powers, second in our happiness or wisdom, and we have come to realize that it is the first and less important of the two promises which it has kept most abundantly.

To those who study her, Nature reveals herself as extraordinarily fertile and ingenious in devising means, but she has no ends which the human mind has been able to discover or comprehend.

Man is, perhaps, no more prone to war than he used to be and no more inclined to commit other evil deeds. But a given amount of ill will or folly will go further than it used to.

Technology made large populations possible; large populations now make technology indispensable.

If we do not permit the earth to produce beauty and joy, it will in the end not produce food, either.

There are some optimists who search eagerly for the skunk cabbage which in February sometimes pushes itself up through the ice, and who call it a sign of spring. I wish that I could feel that way about it, but I do not. The truth of the matter, to me, is simply that skunk cabbage blooms in the winter time.