There is no sadder sight in the world than to see a beautiful theory killed by a brutal fact.

I am too much of a sceptic to deny the possibility of anything...

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.

Trust a witness in all matters in which neither his self-interest, his passions, his prejudices, nor the love of the marvellous is strongly concerned. When they are involved, require corroborative evidence in exact proportion to the contravention of probability by the thing testified.

There is far too much of the feeding-bottle in education and young people ought to be supplied with good intellectual food and then left to help themselves.

The ultimate court of appeal is observation and experiment... not authority.

The Bible account of the creation of Eve is a preposterous fable.