The slow, the never ending approach to truth consists in perpetually forming and testing hypotheses, accepting those at which at the time seem to fit the facts and rejecting the others.
The man of science, like the man of letters, is too apt to view mankind only in the abstract, selecting in his consideration only a single side of our complex and many-sided being.
Even the recognition of an individual whom we see every day is only possible as the result of an abstract idea of him formed by generalization from his appearances in the past.
The abundance, the solidity, and the splendor of the results already achieved by science are well fitted to inspire us with a cheerful confidence in the soundness of its method.
If the test of truth lay in a show of hands or a counting of heads, the system of magic might appeal, with far more reason than the Catholic Church, to the proud motto, 'Quod semper, quod ubique, quod ab omnibus' [always, everywhere, and by all], as the sure and certain credential of its own infallibility.