Social progress means a checking of the cosmic process at every step and the substitution for it of another, which may be called the ethical process; the end of which is not the survival of those who may happen to be the fittest, in respect of the whole of the conditions which obtain, but of those who are ethically the best.

To quarrel with the uncertainty that besets us in intellectual affairs would be about as reasonable as to object to live one's life with due thought for the morrow because no man can be sure he will alive an hour hence.

It sounds paradoxical to say the attainment of scientific truth has been effected, to a great extent, by the help of scientific errors.

I doubt the fact, to begin with, but if it be so even, what is this but in grand words asking me to believe a thing because I like it.

Even in the important matter of cranial capacity, Men differ more widely from one another than they do from the Apes; while the lowest Apes differ as much, in proportion, from the highest, as the latter does from Man.

The birth of science was the death of superstition.

Each such answer to the great question, invariably asserted by the followers of its propounder, if not by himself, to be complete and final, remains in high authority and esteem, it may be for one century, or it may be for twenty: but, as invariably, Time proves each reply to have been a mere approximation to the truth tolerable chiefly on account of the ignorance of those by whom it was accepted, and wholly intolerable when tested by the larger knowledge of their successors.