Though it is incontestable that invention and discovery have been enormously accelerated by often apparently wild suggestions by the imagination, by emotion, and by instinct, it is especially such suggestions which are visited by the most furious onslaughts on the part of the superstitious scientists. When these reject as utter folly imaginings prompted by faith or any other emotions, it is because such suggestions are not only entirely out of harmony with the scientific ideas of the moment, but because they appear so extraordinary, so utterly destructive to the views familiar to them. They would be less positive in face of suggestions and speculations justified by emotion, if they did not constantly forget that every scientific discovery reveals facts which are not only diametrically opposed to opinions previously held, but also so marvellous as to baffle human understanding. Bearing recent scientific discovery in mind, no one will deny the folly of the man who a hundred years ago would have prophetically declared: “What we now have proved true and reasonable will in a hundred years be proved error and folly, and what to us now appears as sheer madness and rank impossibility will then be scientific truth.” Any contemporary scientist, unaffected by scientific superstition, would unhesitatingly acknowledge the probability of present scientific dogmas being declared errors, and that what would now appear as the hallucinations of an overheated imagination may become scientific truth a century hence. Though the narrow-minded scientist who takes up his stand on the so far explored speck of the universe has no right to blame the artist or poet who, guided by emotion and faith, plunges his imagination into the surrounding abyss of the mystical, which no well-balanced mind can ignore, it would be both unjust and absurd to blame the prosaic and plodding scientist who concentrates his whole mind on scientific details, and, to use a happy metaphor of Nordau himself, is building a bridge, arch by arch, out into the unknown. It is good that the Alpine climber should concentrate his attention on the steps he hews in the ice and the safe resting-point he can find for his feet, and not allow his mind to wander in the dark precipice below him or among the lofty peaks he hopes to reach. Man being two personalities, one emotional, the other intellectual, stands in need of the services of both the logical scientist and the emotional artist and poet.