of thought as departments in which _exact_ knowledge was impossible, and whose intellectual examination was therefore fruitless. The Philosophy based on this critical Method was denominated by its founder Positivism. All modern Scientists, with rare exceptions, whether they are disciples of Comte or not, are theoretical Positivists in their modes of investigation, in their unwillingness to accept theories not proven, in their partiality for Facts, and in their devotion to the Inductive Method, although the nature of _proof_ is still but dimly comprehended by them as a body, and much laxity creeps into their practical efforts at demonstration. Under the influence of Positivism, however, the Scientific field is being rapidly cleared of unestablished theories which formerly mingled with it, claiming to be an integral part of its area, and the boundaries of Science are becoming more closely defined. The Inductive Method is enthusiastically eulogized as the source of the success of modern Scientific investigators, as the true Scientific Method, and--except among a few of the most advanced thinkers--as the final word of wisdom in regard to the manner of establishing definite and exact knowledge. The Deductive, often called the _a priori_ Method--in which term the Anticipative or Hypothetical and the true Deductive Method, seen in Mathematical investigations, are not sufficiently discriminated--is, on the other hand, almost everywhere denounced as essentially false, the source of all error; and we are assured that the attempt to work it was the fault of the old world, prior to Bacon, and the cause of its failure to secure great intellectual results. A distinguished thinker, Stephen Pearl Andrews, from whose writings some of these suggestions concerning Methods have been borrowed, points out three sources of confusion in the minds even of the learned themselves, in connection with this subject. First, in the verbal point of view, the terms Induction and Deduction are applied in a way directly the opposite of that which their Etymology would indicate: _In_-duction is used for the _De_-rivation of a Law from Facts, and _De_-duction for the _Intro_-duction of new Facts under the Law. Secondly, the two terms Inductive and Deductive, which are alone usually spoken of, are not enough to designate all the processes involved in the several Scientific Methods; and, thirdly, these terms are sometimes used to denote _Processes_ merely, and sometimes to designate Methods which are merely characterized by the predominance of one or the other of these Processes.