Nietzsche points out that the numerous "logical" conclusions of philosophers have been for the most part _a priori_ propositions, the results of prejudices or desires, and that the syllogistic structures reared to them came as explanations and defences, rather than as dialectic preambles. In their adopting a hypothetical truth as a premise, he sees only the advocacy for a point of view, arguing that in order to erect a system of logic the initial thesis must be proved. Therefore he questions the fundamental worth of certainty as opposed to uncertainty, and of truth as opposed to falsity, thus striking at the very foundations reared by those philosophers who have assumed, without substantiation, that only certainty and truth are valuable. Nietzsche calls these absolutists astute defenders of prejudices, and characterises the verbalistic prestidigitation of Kant as a highly developed form of prejudice-defending. Spinoza, with his mathematical system of reasoning, likewise falls in the category of those thinkers who first assume conclusions and then prepare explanations for them by a process of inverted reasoning. Nietzsche proceeds to pose the instinctive functions against conscious thinking. He asserts that the channels taken by thought are defined by the thinker's nature, and that even logic is influenced by physiological considerations. The whole fabric of philosophic thought is held up to the light of immediate necessity. Going further, he inquires into the "impulse to knowledge." He finds that a specific purpose has always been the actuating force of any philosophy, and that consequently philosophy, even in its most abstract form, has had a residuum of autobiography in it. In fine, that philosophy, far from being a search, has been an aim toward a definite preconceived result. The moral or ethical impulse, being always imperious, has not infrequently resulted in philosophising, and in all such cases knowledge has been used as an instrument. Thus knowledge which led to a philosophical conclusion has been the outgrowth of a personal instinct. In those cases where an impersonal "impulse to knowledge" may have existed, it has led, not into philosophical channels, but into practical and often commercial activities. The scholar has ever remained personal in his quest for philosophical formulas. In Kant's "Table of Categories," wherein that philosopher claimed to have found the faculty of synthetic judgment _a priori,_ Nietzsche finds only a circle of reasoning which begins and ends in personal instinct. And in Kant's discovery of a new moral faculty, Nietzsche sees only sophistical invention, and accounts for its widespread acceptance by the moral state of the Germans at that period. Ignoring the _possibility_ of synthetic judgments _a priori,_ Nietzsche advances the query as to their _necessity,_ and lays stress on the impracticability of truth without _belief._ The inherent falsity or