Important, however, as variety of information and interests doubtless are, one factor must take precedence in the scientist’s equipment--the spirit in which he approaches his scientific work as a whole. In this respect the point that would probably strike most European or, at all events, Continental scientists is the rarity in America of philosophical inquiries into the foundations of one’s scientific position. The contrast with German culture is of course sharp, and in many Teutonic works the national bent for epistemological discussion is undoubtedly carried to a point where it ceases to be palatable to those not to the manner born. Yet this tendency has a salutary effect in stimulating that contempt for mere authority which is indispensable for scientific progress. What our average American student should acquire above all is a stout faith in the virtues of _reasoned nonconformism_, and in this phrase adjective and noun are equally significant. On one hand, we must condemn the blind deference with which too many of our investigators accept the judgments of acknowledged greatness. What can be more ridiculous, e.g., than to make dogmas of the _obiter dicta_ of a man like William James, the chief lesson of whose life is a resentment of academic traditionalism? Or, what shall we think of a celebrated biologist who decides the problem of Lamarckianism by a careful weighing not of arguments but of authorities? No one can approve of the grim ferocity, reminiscent of the literary feuds of Alexander Pope, with which German savants sometimes debate problems of theoretic interest. Yet even such billingsgate as Dührring levelled at Helmholtz is preferable to obsequious discipleship. It testifies, at all events, to the glorious belief that in the republic of learning fame and position count for naught, that the most illustrious scientist shall not be free from the criticism of the meanest _Privatdozent_, But the nonconformism should be rational. It is infantile to cling to leading-strings but it is no less childish to thrust out one’s tongue at doctrines that happen to disagree with those of one’s own clique. Indeed, frequently both forms of puerility are combined: it is easy to sneer with James at Wundt or to assault the selectionists under cover of De Vries’s mutationism. A mature thinker will forego the short and easy but misleading road. Following Fechner, he will be cautious in his belief but equally cautious in his disbelief.