“Science, like life, feeds on its own decay. New facts burst old rules; then newly divined conceptions bind old and new together into a reconciling law.”

“Round about the accredited and orderly facts of every science there ever floats a sort of dust-cloud of exceptional observations, of occurrences minute and irregular and seldom met with, which it always proves more easy to ignore than to attend to... Anyone will renovate his science who will steadily look after the irregular phenomena, and when science is renewed, its new formulas often have more of the voice of the exceptions in them than of what were supposed to be the rules.”

“When a thing is new, people say: ‘It is not true.’ Later, when its truth becomes obvious, they say: ‘It is not important.’ Finally, when its importance cannot be denied, they say: ‘Anyway, it is not new.”

“As a rule we disbelieve all the facts and theories for which we have no use.”

“Psychology is the science of mental life”

“Metaphysics means nothing but an unusually obstinate effort to think clearly. The fundamental conceptions of psychology are practically very clear to us, but theoretically they are very confused, and one easily makes the obscurest assumptions in this science without realizing, until challenged, what internal difficulties they involve.”

“This sadness lies at the heart of every merely positivistic, agnostic, or naturalistic scheme of philosophy. 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. In the practical life of the individual, we know how his whole gloom or glee about any present fact depends on the remoter schemes and hopes with which it stands related. Its significance and framing give it the chief part of its value. Let it be known to lead nowhere, and however agreeable it may be in its immediacy, its glow and gilding vanish. The old man, sick with an insidious internal disease, may laugh and quaff his wine at first as well as ever, but he knows his fate now, for the doctors have revealed it; and the knowledge knocks the satisfaction out of all these functions. They are partners of death and the worm is their brother, and they turn to a mere flatness.”