No one can read the history of astronomy without perceiving that Copernicus, Newton, Laplace, are not new men, or a new kind of men, but that Thales, Anaximenes, Hipparchus, Empodocles, Aristorchus, Pythagorus, Oenipodes, had anticipated them.
The student is to read history actively and not passively; to esteem his own life the text, and books the commentary. Thus compelled, the muse of history will utter oracles as never to those who do not respect themselves.