My father never permitted anything which I learnt to degenerate into a mere exercise of memory. He strove to make the understanding not only go along with every step of the teaching but...precede it.

The prevailing tendency to regard all the marked distinctions of human character as innate, and in the main indelible, and to ignore the irresistible proofs that by far the greater part of those differences, whether between individuals, races, or sexes are such as not only might but naturally would be produced by differences in circumstances, is one of the chief hinderances to the rational treatment of great social questions, and one of the greatest stumbling blocks to human improvement.

To think that because those who wield power in society wield in the end that of government, therefore it is of no use to attempt to influence the constitution of the government by acting on opinion, is to forget that opinion is itself one of the greatest active social forces. One person with a belief is a social power equal to ninety-nine who have only interests.

It is given to no human being to stereotype a set of truths, and walk safely by their guidance with his mind's eye closed.

It appears, then, to be a condition of a genuinely scientific hypothesis, that it be not destined always to remain an hypothesis, but be certain to be either proved or disproved by.. .comparison with observed facts.

Customs are made for customary circumstances, and customary characters.

To discover to the world something which deeply concerns it, and of which it was previously ignorant; to prove to it that it had been mistaken on some vital point of temporal or spiritual interest, is as important a service as a human being can render to his fellow creatures.