Our common dependence upon the history of thought for all our reflective undertakings is unquestionable. Our best originality, if we ever get any originality, must spring from this very dependence. Doctrines of genuinely revolutionary significance are indeed in the history of speculation, and they ought to be so. Of lesser surprises, of marvels, of beautifully novel insights, all the greater highways of speculation are full; and yet most of the marvels are only such in so far as they are set off upon a very large background of the historically familiar. Only a very few times in the history of thought is the continuity of the evolution distinctly broken. The novelties are elsewhere only relative, and get their very value from the fact that they are so.