I laughed at the unseen world. Only the real was real, I contended, and what one did not perceive, was not, could not be. I believed in a mechanical universe. Chemistry and physics explained everything. "Can no being be?" he demanded in reply. I said that his question was but the major promise of a fallacious Christian Science syllogism. Oh, believe me, I know my logic, too. But he was very stubborn. I never had any patience with philosophic idealists. * * * * * Once, I made to him my confession of faith. It was simple, brief, unanswerable. Even as I write it now I know that it is unanswerable. Here it is. I told him: "I assert, with Hobbes, that it is impossible to separate thought from matter that thinks. I assert, with Bacon, that all human understanding arises from the world of sensations. I assert, with Locke, that all human ideas are due to the functions of the senses. I assert, with Kant, the mechanical origin of the universe, and that creation is a natural and historical process. I assert, with Laplace, that there is no need of the hypothesis of a creator. And, finally, I assert, because of all the foregoing, that form is ephemeral. Form passes. Therefore we pass." I repeat, it was unanswerable. Yet did he answer with Paley's notorious fallacy of the watch. Also, he talked about radium, and all but asserted that the very existence of matter had been exploded by these later-day laboratory researches. It was childish. I had not dreamed he could be so immature. How could one argue with such a man? I then asserted the reasonableness of all that is. To this he agreed, reserving, however, one exception. He looked at me, as he said it, in a way I could not mistake. The inference was obvious. That he should be guilty of so cheap a quip in the midst of a serious discussion, astounded me. * * * * * The eternity of forms. It is ridiculous. Yet is there a strange magic in the words. If it be true, then has he not ceased to exist. Then does he exist. This is impossible. * * * * * I have ceased exercising. As long as I remain in the room, the hallucination does not bother me. But when I return to the room after an absence, he is always there, sitting at the desk, writing. Yet I dare not confide in a physician. I must fight this out by myself. * * * * * He grows more importunate. To-day, consulting a book on the shelf, I turned and found him again in the chair. This is the first time he has dared do this in my presence. Nevertheless, by looking at him steadily and sternly for several minutes, I compelled him to vanish. This proves my contention. He does not exist. If he were an eternal form I could not make him vanish by a mere effort of my will. * * * * *