indeed, the whole doctrine of knowledge—stands on a different plane from that in the Treatise, and that custom is no longer represented as a "blind instinct," but as the "great guide of human life." It seems to me that the conclusions concerning matters of fact stand upon the same basis in both works. They rest ultimately on custom, and custom is of the same nature, and plays the same part, in the Inquiry as in the Treatise. It is an instinct which, at times, acts more unerringly than does reason, but yet, "like other instincts, may be fallacious and deceitful."
The author thinks that Hume's doctrine of probability has undergone a change in the Inquiry, and that the defective treatment which the subject there receives, is due to the change in his doctrine of belief. He criticises my article on this point, but I think he adopts an extreme position. In the Treatise, Hume deals with probability under three heads: philosophical probability of chance, philosophical probability of cause, and unphilosophical probability. In the Inquiry, he deals with it under the first two, the discussion of unphilosophical probability being entirely omitted. Since, however, he says in the Treatise that unphilosophical probability is "derived from the same principles" as philosophical probability, this omission does not seem to be of special significance. In philosophical probability a conclusion is the result of three processes: (1) a summing up of the favorable instances; (2) a summing up of the unfavorable instances; (3) the subtracting of the latter sum from the former. The remainder represents the probability and force of the conclusion or judgment. In the Inquiry, in the treatment of probability both of chance and of cause, this third process is not explicitly stated. But neither is it mentioned in the first account that is given of probability of cause in the Treatise. The three processes are described fully in the account of probability of chance; the first two are described in the account of probability of cause; and then Hume says: "this operation of the mind has been so fully explained in treating of the probability of chance that I need not here endeavor to render it more intelligible." That is, the third process is implied, although not distinctly mentioned—it is mentioned afterwards. It is also implied in the discussion in the Inquiry. The explicit statement of it is omitted there, evidently because Hume could not say so much in two and a half pages as he had said in sixteen pages of the Treatise. It must also be borne in mind that Hume did not write the Inquiry to repudiate the Treatise, but rather to explain it. The repudiation of the Treatise was an afterthought. Moreover, the doctrine of belief, as held by Hume in the discussion of the subject of probability in both works, is exactly the same.
According to Dr. Brede, the new subjects introduced in the Inquiry are liberty and necessity, miracles, a future state, and a Personal Providence. No hint is given by him that liberty and necessity had been fully discussed in Book II of the Treatise of Human Nature. He thinks that the discussion of these questions is inserted in the Inquiry because of the change (1) in Hume's point of view, and (2) in his attitude toward religion. It was
