Knowledge reaches the mind in two forms, for which there are in most languages, though not in modern English, two distinct expressions, _connaitre_ and _savoir_, _kennen_ and _wissen_. The former relates to knowledge through sensation, the latter through intellection; the former cannot be rendered in words, the latter can be; the former is reached through immediate perception, the latter through logical processes. For example: an odor is something we may certainly know and can identify, but we cannot possibly describe it in words; justice on the other hand may be clearly defined to our mind, but it is equally impossible to translate it into sensation. Nevertheless, it is generally agreed that the one of these processes is, so far as it goes, as conclusive as the other, and that they proceed on essentially the same principles.[22-1] Religious philosophy has to do only with the second form of knowledge, that reached through notions or thoughts. The enchainment or sequence of thoughts in the mind is at first an accidental one. They arise through the two general relations of nearness in time or similarity in sensation. Their succession is prescribed by these conditions, and without conscious effort cannot be changed. They are notions about phenomena only, and hence are infinitely more likely to be wrong than right. Of the innumerable associations of thought possible, only one can yield the truth. The beneficial effects of this one were felt, and thus by experience man slowly came to distinguish the true as what is good for him, the untrue as what is injurious. After he had done this for a while, he attempted to find out some plan in accordance with which he could so arrange his thoughts that they should always produce this desirable result. He was thus led to establish the rules for right reasoning, which are now familiarly known as Logic. This science was long looked upon as a completed one, and at the commencement of this century we find such a thinker as Coleridge expressing an opinion that further development in it was not to be expected. Since then it has, however, taken a fresh start, and by its growth has laid the foundation for a system of metaphysics which will be free from the vagaries and unrealities which have thrown general discredit on the name of philosophy. In one direction, as applied logic and the logic of induction, the natural associations of ideas have been thoroughly studied, and the methods by which they can be controlled and reduced have been taught with eminent success. In this branch, Bentham, Mill, Bain, and others have been prominent workers.