There is nothing of permanent value (putting aside a few human affections) nothing that satisfies quiet reflection--except the sense of having worked according to one's capacity and light to make things clear and get rid of cant and shams of all sorts.

Science commits suicide when it adopts a creed.

My fundamental axiom of speculative philosophy is that materialism and spiritualism are opposite poles of the same absurdity-the absurdity of imagining that we know anything about either spirit or matter.

Regarded anatomically, the resemblances between the foot of Man and the foot of the Gorilla are far more striking and important than the differences... be the differences between the hand and foot of Man and those of the Gorilla what they may the differences between those of the Gorilla and those of the lower Apes are much greater.

Fact I know; and Law I know; but what is this Necessity, save an empty shadow of my own mind's throwing?

If there is anything in the world which I do firmly believe in, it is the universal validity of the law of causation.

From the dawn of exact knowledge to the present day, observation, experiment, and speculation have gone hand in hand; and, whenever science has halted or strayed from the right path, it has been, either because its votaries have been content with mere unverified or unverifiable speculation (and this is the commonest case, because observation and experiment are hard work, while speculation is amusing); or it has been, because the accumulation of details of observation has for a time excluded speculation.