Psychology, therefore, cannot be limited to the study of the phenomena of our superconsciousness by means of introspection alone, for it would then be impossible. Every individual would only have the psychology of his own subjectivism, like the old scholastic spiritualists, and would have to doubt the existence of the outer world, including his fellow-men. The deductions of analogy, the natural scientific induction, the comparison of the experience of our five senses, all prove to us the existence of the outer world and of our fellow-creatures, and of the psychology of the latter. At the same time, these factors prove to us that there is a psychology of animals - a comparative psychol-ogy. Lastly, our own psychology, taken without reference to the activity of our brains, is an incomprehensible fragment, which teems with contradictions, and which, above all, appears to contradict the law of the preservation of energy.

It is further clear from this very simple argument that a psychology which ignores the activity of the brain must be an impossibility. The contents of our superconscionsness is always influenced and caused by hypoconceived activities of the brain.1 It cannot be understood without these activities. On the other band, we can only understand the full value and the basis of the complicated organization of our brain, if we regard it in the inner illumination of out consciousness, and if we amplify this observation by comparing the contents of consciousness of our fellow-men. The last mentioned is rendered possible for us by means of spoken and written speech - the "coinage" of thinking - which offer detailed deductions of analogy. The mind must, therefore, be studied from without and from within. Outside ourselves, it is true, the former can only be carried out by deduction of analogy; but as this is the only means at our disposal, we must employ it.

1There is no such thing as an inactive consciousness without contents. The only term remaining to be applied to this is "pure nothing," in its Abstract sense.

Talleyrand said that speech has been given to man, not for the expression, but for the concealing of his thoughts. Apart from this, some people honestly place a very different construction on words than do others. A scientist, an artist, a peasant, a woman, a child, an uncivilized Wedda of Ceylon, interpret the same words of the same language quite differently; but even the same person may interpret the words differently, according to his mood and the connection in which they are used. From this we may infer that for the psychologist, and especially for the physician for diseases of the brain - and I speak as one - mimicry, expression, and action of a person often reveal the true internal man better than what he says. In the same way, also, the movements and actions of animals have the importance of a "speech" for us. The psychological value of these must not be undervalued. Besides, the anatomy, physiology, and pathology of human and animal brains have brought forward the incontestable proof that the characters of our mind depend on the quality, quantity, and integrity of the living brain, and are therefore identical with it. A living brain without a mind can no more exist than can a mind without a brain, and every normal or pathological change of the activity of the mind corresponds to a normal or pathological change of the activity of the neurokymes of the brain - i.e., of its nerve elements. What we recognize introspectively in our consciousness are synthesized activities of the brain.

' In his novel, "La femme de trente ans" I (published by Calman Levy), p. 127, Balzac writes: " II existe des pensees auxquelles nous obeissons sans les connattre: elles sont en nous a notre insu. Quoique cette reflexion puisse parattre plus puradoxale que vraie, cheque personne de bonne foi en trouvera mille preuves dans eta vie. Balzac was a good psychologist. He had already recognized (he value of the hypo conceived influences.

We can therefore accept the theory of identity regarding the relations of pure psychology (introspection) to the physiology of the brain (the observation of the activity of the brain from without) as long as the facts are consistent.

Kopernik's theory is also a supposition. We can accept with Kopernik that the earth and the planets revolve around the sun, and not the reverse - i.e., the sun and stars revolving around us. Still this is not actually proved - at all events, not deductively. One can, however, still adopt the reverse view with Ptolemy. But the facts which were formerly known, and those especially which have been observed more recently, all coincide with Kopernik's theory, and consistently support it in such a way that we must believe in it. On the other hand, one can only accept the views of Ptolemy "by presuming the most wonderful and most unlikely erratic movements of the stare. All facts speak more and more against this view. There would be a most confused chaos, and a number of laws of magnetism, etc, which are at present universally confirmed would be overthrown. We must therefore refuse Ptolemy's theory, more especially as, by means of Kopernik's views, and of their development in the astronomy of to-day, one can prophesy celestial events exactly, and even the advent of new satellites. This would be impossible with Ptolemy's theory.