'The first of these phenomena may be in part explained as the youthful exuberance of the new age which has risen in the realm of science no less than in the world of politics. If this exuberance greeted with rapture the dawn of the intellectual renascence, and without profounder labour at once set about enjoying the Idea and revelling for a while in the hopes and prospects which it offered, one can more readily forgive its excesses; because it is sound at heart, and the surface vapours which it had suffused around its solid worth must spontaneously clear off. But the other spectacle is more repulsive; because it betrays exhaustion and impotence, and tries to conceal them under a hectoring conceit which acts the censor over the philosophical intellects of all the centuries, mistaking them, but most of all mistaking itself. 'So much the more gratifying is another spectacle yet-to be noted; the interest in philosophy and the earnest love of higher knowledge which in the presence of both tendencies has kept itself single-hearted and without affectation. Occasionally this interest may have taken too much to the language of intuition and feeling; yet its appearance proves the existence of that inward and deeper-reaching impulse of reasonable intelligence which alone gives man his dignity,--proves it above all, because that standpoint can only be gained as a _result_ of philosophical consciousness; so that what it seems to disdain is at least admitted and recognised as a condition. To this interest in ascertaining the truth I dedicate this attempt to supply an introduction and a contribution towards its satisfaction.'