other manifestations as to necessitate a specific designation. By adopting the term personality, we should affirm our belief in the existence of some form of being, which, for us, is persistently unlike every other form of being with which we come into relation. Here the element of speculation, which is a necessary part of all reasoning, appears. Whether we accept correlation or personality, we accept what can no more be directly known than the mortality of men now living, or the return of the seasons. All reasoning is beyond the facts, and is in this a speculation; but reasoning need be no more an unsafe guide on such subjects as the one before us than on any of the complex affairs where we gladly trust its teachings. Our demand of Reason must be that, though she lead us beyond the facts, she shall never lead us contrary to the facts. Again, I would say, it should be recognized that neither of the conclusions above indicated is a solution of the mystery attendant upon consciousness. The pride of the little scientists induces them all too often to declare that, by the first of these alternatives, they have cleared away the obscurity which they love to call metaphysical and let in the white light of comprehension.
So, in turn, the other party, seizing hold of the fact of personality, forthwith affirm that, by it, man's immateriality, immortality, and divinity, are forever made visible in the light of consciousness. All this is quite aside from that inferential process which, as reasoning beings, we should prescribe for ourselves. Is the relation between brain and consciousness one of correlation; may we, according to the evidence, believe it to be one of correlation? Physiological materialism is an extension of the doctrine of correlation to consciousness. It is needful to know what is meant by correlation. Correlation is a necessary, reciprocal production. "Any force capable of producing another may be produced by it. Each mode of force is capable of producing the others, and none of them can be produced but by some other as an anterior force. The various affections of matter, heat, light, electricity, have a reciprocal dependence; either may produce or be convertible into any of the others." The materialism of physiology extends this doctrine of correlation to consciousness. The well-worn language of Professor Huxley ("Darwin and his Critics") is again in point. "As the electric force, the light-waves and the nerve-vibrations caused by the impact of the light-waves on the retina are all expressions of the molecular changes which are taking place in the elements of the battery, so consciousness is, in the same sense, an expression of the molecular changes which take place in that nervous matter which is the organ of consciousness." A short sentence from Dr. Carpenter to the same effect: "There is just the same evidence of what has been termed correlation between nerve-force and that primary state of mental activity which we call sensation that there is between light and nerve-force." Now, the proposition, fundamental to my paper, is that such a conclusion can not rationally be drawn, un-
