Let sanguine healthy-mindedness do its best with its strange power of living in the moment and ignoring and forgetting, still the evil background is really there to be thought of, and the skull will grin in at the banquet.

When a superior intellect and a psychopathic temperament coalesce in the same individual, we have the best possible condition for the kind of effective genius that gets into the biographical dictionaries.

Once you accept an idea, it's an idea whose time has come.

Since belief is measured by action, he who forbids us to believe religion to be true, necessarily also forbids us to act as we should if we did believe it to be true.

Why may we not be in the universe, as our dogs and cats are in our drawingrooms and libraries?

The greatest empiricists among us are only empiricists on reflection: when left to their instincts, they dogmatize like infallible popes.

My thinking is first and last and always for the sake of my doing, and I can only do one thing at a time.