In the higher animals there is added to the sinpler automatic part of the nervous system a far more intricate structure, called the influential nervous mechanism. Professor Draper represents the contrast between the automatic and the influential part of the nervous system by this ideal figure (DRAPER, Human Physiology, p. 282), which I here reproduce line for line. It is substantially a lower curve and an upper curve, - the one automatic, the other influential, and the two bound together by nervous threads. In all physiology, outside the supreme topic of bioplasm, I know nothing which is so suggestive as this contrast between the automatic and the influential nerve-arcs. Here, assuredly, is a majestic mount of vision upon which the philosophy of the relations between body and soul, matter and mind, must often pace to and fro.

2. Plants and many animals possess only the automatic arcs.

3. Such organizations as possess only the automatic arcs are automata; and, although they have life, they cannot, in the strict sense of the word, be said to possess souls including free-will and conscience.

The contrast between the influential and the automatic is that between freedom and necessity. It is that between man, with the power of choice, and your poor honey-bee, who is supposed to work as an automaton. The bee has not the influential arc: it has only the automatic nerves. Accordingly, by instinct it has built its cell in the same way age after

age. Two bees under precisely the same circumstances will do precisely the same things.

But this upper arc, which is possessed by man, is called influential, and not automatic, because it is the seat of activities of a free sort. This is the keyboard of your invisible musician: this is the white ivory shaped by no mortal fingers, and on which life plays. [Applause.]

Gentlemen, I have been accused of being rhetorical; but a man who wishes to dazzle by rhetoric does not talk in twenty-eighthlies and forty-ninthlies, as I have sometimes done. Any one, however, who wishes to convince by cool precision, very naturally employs numerals. You will allow me, therefore, to number the points of a discussion, which must be crowded, and which would nevertheless be clear.

Just here expose themselves in more than glimpses the fascinating questions as to the difference between instinct and reason, and as to the immortality of instinct. Animals that possess only the automatic nerve-arcs have only instinct for their guidance: they have life, but not free-wills and consciences. Later in this course of lectures, I shall discuss the question, whether, after death, there is a survival of the immaterial principle in animals that are mere automata. Here and now I emphasize only this broad distinction between the influential and automatic nerve-arcs, a physical fact, without any haze either in its margin or its contents. God materializes. In the universe of forms, as well as in that of forces, the Divine language has no empty syllable.

Perhaps this invisible musician, with Gyges' ring on his finger, has not been left without a witness of himself in the whitish-gray keyboard of the human organ. Perhaps the contrast between the automatic and influential nerve-arcs is just as important a fact in the instrument God has made as the distinction between your musician and the man who moves the bellows behind the organ is in the instrument man has made. Among the automatic and influential nerve-arcs, all philosophy ought to stand listening with hushed breath.

4. Man possesses in abundance both the automatic and influential arcs.

5. Whatever animal possesses the influential arcs has a depository, magazine, or reservoir of force not dependent on external impressions.

Aristotle noticed with great keenness of interest the fact that men awake before they open their eyes. Professor Bain regards that circumstance, with which we are all familiar, as one out of thousands of proofs that external irritation is not necessary always to internal activity.

By the way, Aristotle was accustomed to assert that the most interesting portion of human knowledge is that which refers to what he called the animating principle of physical organisms. We are beginning to think, I hope, that what is called bioplasm is the most interesting by far of all the objects know to physical science. That, in substance, is an opinion two thousand years old. Aristotle defined the animating principle as the cause of form in organ

isms (Aristotle de Anima, passim). This to him was the most alluring of all the topics open to Greek philosophy. He said often, that, if we ought to be interested in a theme in proportion to its dignity, certainly nothing could be more entrancing than the study of the animating principle.

6. In man the influential arc is the seat of intellect, free-will, and conscience.

7. But, as man possesses the automatic arc also, many of his actions are automatic.

We must expect to find in some animals which have a much more perfect automatic nervous mechanism than man, instincts, and, apparently, spontaneous movements, of the most marvellous kinds. I am not asserting that man is not in some respects an automaton; but he is by no means as good a one as might be chosen if the power of automatic nervous action is to be shown. Professor Huxley went before a great audience at the Belfast meeting of the British Association for the Advancement of Science, and took a headless frog, and put it on the back of his hand, and then turned his hand slowly over; and the frog kept his place till the hand had been reversed, and the frog stood in the palm. (HUXLEY'S Address on the Question, Are Animals Automata?) Now, said Professor Huxley, is there any will concerned in that? Is not this the result of purely physical stimulation of the frog's nerves? Have we not here an automaton? He meant to puzzle the world about the freedom of the human soul. But the bioplasts wove that frog too. After the automatic mechanism

is woven, such results are very well known to follow the action of the merely automatic part of the nervous system. A frog with his head cut off you may put on the back of your hand, and you may turn the hand over, and the frog will keep its place meanwhile without assistance, and stand on your palm. Of course, there is no action of the cerebral hemispheres there. The irritation of the feet has such an effect as to cause the muscles to enable them to cling to their support; just as, while the perching bird sleeps, the perch itself stimulates to action the muscles that cause it to be clasped by the bird's feet. Will you please notice that you have no right to be puzzled by any number of facts like these, and that all there is in Huxley's famous experiment is admitted truth concerning the automatic part of the nervous system, and that the puzzle consists in putting that fragment for the whole ?

8. As in man, the automatic and the influential nervous arcs are blended together by innumerable commissures, and are yet perfectly distinguishable by study, so the automatic and the free activities of man are, in experience, most intricately blended together, and yet are perfectly distinguishable by careful attention.

9. Sometimes the former may become so powerful as to overcome the latter; and sometimes the latter may overcome the former.

10. The power of habit, and, to a great extent, that of emotion, depends on the action of the automatic arcs.