...These healers...my intellect has been unable to assimilate their theories....But their facts are patent and startling; and anything that interferes with the multiplication of such facts, and with our freest opportunity of observing and studying them, will, I believe, be a public calamity.

Science herself consults her heart when she lays it down that the infinite ascertainment of fact and correction of false belief are the supreme goods for man.

There are no differences but differences of degree between different degrees of difference and no difference.

Pretend what we may, the whole man within us is at work when we form our philosophical opinions.

The most immutable barrier in nature is between one man's thoughts and another's.

All the higher, more penetrating ideals are revolutionary. They present themselves far less in the guise of effects of past experience than in that of probable causes of future experience, factors to which the environment and the lessons it has so far taught us must learn to bend.

Man lives by habits indeed, but what he lives for is thrill and excitements. ... From time immemorial war has been ... the supremely thrilling excitement.