It is the man of science, eager to have his every opinion regenerated, his every idea rationalized, by drinking at the fountain of fact, and devoting all the energies of his life to the cult of truth, not as he understands it, but as he does not yet understand it, that ought properly to be called a philosopher. To an earlier age knowledge was power — merely that and nothing more; to us it is life and the summum bonum. Emancipation from the bonds of self, of one's own prepossessions, importunately sought at the hands of that rational power before which all must ultimately bow, — this is the characteristic that distinguishes all the great figures of nineteenth-century science from those of former periods.

"The Century's Great Men in Science" in The 19th Century : A Review of Progress During the Past One Hundred Years in the Chief Departments of Human Activity (1901), published by G. P. Putnam's Sons.