—In this place I can't permit myself to omit a psychology of "belief," of the "believer," for the special benefit of "believers." If there remain any today who do not yet know how indecent it is to be "believing"—or how much a sign of décadence, of a broken will to live—then they will know it well enough tomorrow. My voice reaches even the deaf.—It appears, unless I have been incorrectly informed, that there prevails among Christians a sort of criterion of truth that is called "proof by power." "Faith makes blessed: therefore it is true."—It might be objected right here that blessedness is not demonstrated, it is merely promised: it hangs upon "faith" as a condition—one shall be blessed because one believes…. But what of the thing that the priest promises to the believer, the wholly transcendental "beyond"—how is that to be demonstrated?—The "proof by power," thus assumed, is actually no more at bottom than a belief that the effects which faith promises will not fail to appear. In a formula: "I believe that faith makes for blessedness—therefore, it is true."…But this is as far as we may go. This "therefore" would be absurdum itself as a criterion of truth.—But let us admit, for the sake of politeness, that blessedness by faith may be demonstrated (—not merely hoped for, and not merely promised by the suspicious lips of a priest): even so, could blessedness—in a technical term, pleasure—ever be a proof of truth? So little is this true that it is almost a proof against truth when sensations of pleasure influence the answer to the question "What is true?" or, at all events, it is enough to make that "truth" highly suspicious. The proof by "pleasure" is a proof of "pleasure"—nothing more; why in the world should it be assumed that true judgments give more pleasure than false ones, and that, in conformity to some pre–established harmony, they necessarily bring agreeable feelings in their train?—The experience of all disciplined and profound minds teaches the contrary. Man has had to fight for every atom of the truth, and has had to pay for it almost everything that the heart, that human love, that human trust cling to. Greatness of soul is needed for this business: the service of truth is the hardest of all services.—What, then, is the meaning of integrity in things intellectual? It means that a man must be severe with his own heart, that he must scorn "beautiful feelings," and that he makes every Yea and Nay a matter of conscience!—Faith makes blessed: therefore, it lies….