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has given us mind into the bargain. It is, I say, at least possible. We know too little of the facts cited as analogical to be able to say more.

But there is another and a stronger objection. We know nothing of mind, at first hand, except as it exists in man. Elsewhere, we are forced to rely upon the 'objective criteria,' of which more presently. What right, now, has the interactionist to bring mind into the organic series at any point lower than man? Why is he not bound, under the law of parsimony, to keep mind out until its presence can be positively demonstrated? I think that the answer is plain; he is so bound, unless he can show cause for believing that mind, were it present, would be of service to the organism in the struggle for existence. As he has called upon his opponent to 'prove the necessity of mind at the first appearance of life,' so we might retort that he is himself bound to show the indispensableness of mind to the struggling organism. But we will let the more modest phrasing stand, and proceed to an examination of the arguments.

The locus classicus for the survival value of consciousness is Chapter V. of James' 'Principles of Psychology.' The arguments are three.

(a) "The brain is an instrument of possibilities, but of no certainties. . . . Its hair-trigger organization makes of it a happy-go-lucky, hit-or-miss affair. It is as likely to do the crazy as the sane thing at any given moment. . . . But the consciousness, with its own ends present to it, and knowing also well which possibilities lead thereto and which away, will, if endowed with causal efficacy, reinforce the favorable possibilities, and repress the unfavorable and indifferent ones."

The facts bear out this 'a priori analysis'; for

'consciousness is only intense when nerve-processes are hesitant.' (b) The phenomena of vicarious function 'seem to form another bit of circumstantial evidence.' "Nothing seems at first sight more unnatural than that [the remaining parts of the brain] should vicariously take up the duties of a part now lost without those duties as such exerting any persuasive or coercive force." (c) "If pleasures and pains have no efficacy, one does not see. . . why the most noxious acts, such as burning, might not give thrills of delight, and the most necessary ones, such as breathing, cause agony."

The first of these arguments is little less than amazing. It asserts that the brain, the central and ruling organ of the whole body, has been so far exempt from the influence of natural selection that it is 'indeterminate,' 'an instrument of possibilities,' 'as likely to do the crazy as the sane thing' I 'The natural law of an organ constituted after this fashion can be nothing but a law of caprice.' Does such 'a priori analysis' commend itself to the neurologist? I should rather say that the brain, combining as it does an immense structural complexity with great architectural simplicity, has been stably and determinately molded for the part which it plays in the economy of the organism; that it is a marvelously reliable organ, definitely disposed