The strongest feelings assigned to the conscience are not moral feelings at all; they express merely physical antipathies.

Nietzsche said that the earth has been a madhouse long enough. Without contradicting him we might perhaps soften the expression, and say that philosophy has been long enough an asylum for enthusiasts.

... even if Lucretius was wrong, and the soul is immortal, it is nevertheless steadily changing its interests and its possessions.Our lives are mortal if our soul is not; and the sentiment which reconciled Lucretius to death is as much needed if we are to face many deaths, as if we are to face only one.

We are not compelled in naturalism, or even in materialism, to ignore immaterial things; the point is that any immaterial things which are recognized shall be regarded as names, aspects, functions, or concomitant products of those physical things among which action goes on.

The tendency to gather and to breed philosophers in universities does not belong to ages of free and humane reflection: it is scholastic and proper to the Middle Ages and to Germany.

Spirit itself is not human; it may spring up in any life... it may exist in all animals, and who know in how many undreamt-of beings, or in the midst of what worlds?

The whole machinery of our intelligence, our general ideas and laws, fixed and external objects, principles, persons, and gods, are so many symbolic, algebraic expressions. They stand for experience; experience which we are incapable of retaining and surveying in its multitudinous immediacy. We should flounder hopelessly, like the animals, did we not keep ourselves afloat and direct our course by these intellectual devices. Theory helps us to bear our ignorance of fact.