department of the self, which he called the "passions," in which the course and content of mind is determined by bodily conditions. Extending this conception to the whole province of mind, they employed it to demonstrate the thorough-going subordination of mind to body. La Mettrie, a physician and the author of a book entitled "L'Homme Machine," was first interested in this thesis by a fever delirium, and afterward adduced anatomical and pathological data in support of it. The angle from which he views human life is well illustrated in the following: "What would have sufficed in the case of Julius Cæsar, of Seneca, of Petronius, to turn their fearlessness into timidity or braggartry? An obstruction in the spleen, the liver, or the _vena portae_. For the imagination is intimately connected with these viscera, and from them arise all the curious phenomena of hypochondria and hysteria. . . . 'A mere nothing, a little fibre, some trifling thing that the most subtle anatomy cannot discover, would have made two idiots out of Erasmus and Fontenelle.'"[250:15] [Sidenote: Radical Materialism. Mind as an Epiphenomenon.] § 116. The extreme claim that the soul is a physical organ of the body, identical with the brain, marked the culmination of this militant materialism, so good an instance of that over-simplification and whole-hearted conviction characteristic of the doctrinaire propagandism of France. Locke, the Englishman, had admitted that possibly the substance which thinks is corporeal. In the letters of Voltaire this thought has already found a more positive expression: "I am body, and I think; more I do not know. Shall I then attribute to an unknown cause what I can so easily attribute to the only fruitful cause I am acquainted with? In fact, where is the man who, without an absurd godlessness, dare assert that it is impossible for the Creator to endow matter with thought and feeling?"[251:16] Finally, Holbach, the great systematizer of this movement, takes the affair out of the hands of the Creator and definitively announces that "a sensitive soul is nothing but a human brain so constituted that it easily receives the motions communicated to it."[251:17]