6. The medulla oblongata is a complex center of reflex co-ordination.

7. The mesencephalon and the cerebellum are coordinating centers of the activities connected with the maintenance of animal-life.

8. Removal of the hemispheres destroys the power of volitional movements; destroys memory, conscious sensation, ideation, intelligence, and the instinct of selfpreservation.

9. The cerebrum is the seat of intelligence, volition, memory, reason, and judgment.

10. Volition, so far as physiology enables us to determine, has its origin in the gray substance of the cerebrum.

II. The cerebral hemispheres are the especial organ of the mind.

12. It is highly probable that definite sections of the brain are especially concerned in certain muscular movements and in certain intellectual activities.

13. The organs of sensation-touch, sight, hearing, taste, and smell-are localized in the cerebrum.

14. The power of willing, especially of willing muscular movements, and most probably of willing to retain ideas under the light of reason till a conclusion is reached, is localized in certain sections of the gray matter of the cerebrum.

15. The optic thalami are centers of convergence of sensory fibers; and consequently their destruction annihilates all sensation and destroys consciousness.

16. The corpora striata are the center in which habitual movements become organized.

17. In the absence of the hemispheres, the lower centers are incapable of originating any movements, except those which are purely reflex.

18. These lower ganglia are centers of immediate responsive actions; and of these only; self-conditioned activity being a function of the hemispheres, and of these alone.

19. The exercise of memory, reason, and judgment is conditioned upon materials furnished by sensory impressions, except so far as certain categories of thought are concerned.

20. The entire absence of the cerebellum leaves all mental processes unimpaired.

CHAPTER XXI.

MOLECULAR VIBRATIONS IN THE BRAIN.

MENTAL activities are not identical with molecular vibrations in the brain, nor are they a simple result of such vibrations.

In support of this proposition the following considerations are presented:

1. The concurrent testimony of eminent physiologists. Dr. J. C. Dalton says,

"The intermediate process between the sensation and the volition may be short and simple; or it may be long and complicated, involving the combined suggestion of many successive ideas. There can be little doubt that in either case, it is accompanied by actions of some kind in the gray substance of the cerebral hemispheres. But the nature of the nervous process accompanying mental action is unknown."-Human Physiology, p. 426.

If the "nervous process," whatever its unknown character may be, only accompanies "mental action," it is not, in the opinion of this author, identical with intellectual activity; and if the nature of this nervous process is unknown, we are not authorized in asserting that it is "molecular vibration" of which thought is a result. Dr. David Ferrier affirms:

"That the brain is the organ of the mind, and that mental operations are possible only in and through the brain, is now so thoroughly well established and recognized that we may without further question start from this as an ultimate fact."

"But how it is that molecular changes in the brain-cells coincide with modifications of consciousness; how, for instance, the vibrations of light falling on the

retina excite the modification of consciousness termed a visual sensation, is a problem which cannot be solved. We may succeed in determining the exact nature of the molecular changes which occur in the brain-cells when a sensation is experienced, but this will not bring us one whit nearer the explanation of the ultimate nature of that which constitutes the sensation. One is objective and the other subjective, and neither can be expressed in terms of the other. We cannot say that they are identical, or even that the one passes into the other."— Functions of the Brain, p. 280-281.

If, as is here affirmed, the brain is the organ of the mind, then it is fair, no doubt, to assert that mind exists as an entity which is not identical with brain, nor with the molecular vibrations of brain-tissue; and equally legitimate to declare that mind is not a product of physical changes. An agent cannot be identical with him in whose service he is engaged; consequently, brain cannot be the agent of mind and at the same time identical with mind. Again, if brain is the agent of mind, then mind cannot be a product of brain, for that would be to suppose that an agent creates, or at least occasions, the existence of him into whose service he enters; but reason clearly asserts that an agent cannot exist, as an agent, antecedent to the existence of him whom he serves; and though he who employs agents can create them, or at least can fashion them to his liking and tutor them to obey his mandates, or dismiss them from his service,-it is a gross perversion of ideas to assert, or even to imagine, that an agent creates, or even occasions the existence of him who employs such service. Consequently, if mind is a result of molecular vibrations in the brain, physiologists, instead of recognizing "the brain as an organ of the mind," ought to have been able to recognize mind as an agent or organ of the brain, and should have expressed themselves in language fitted to convey this idea.

It is therefore legitimate to assert, that as physiolo

gists concur in regarding it as a "thoroughly well established fact that the brain is the organ of the mind," their united testimony favors the conclusion that mind is neither matter, nor a product of matter; that intellectual force is not identical with brain-substance, nor capable of being produced by its transmutations or by its molecular vibrations. They do not mean to convey the impression that mind is identical with its organ; nor that it is a succession of "trills" in its own organ.

Dr. W. B. Carpenter affirms:

...

"It is now generally admitted that we neither know nor can know, anything of matter, save through the medium of the impressions it makes on our senses; and these impressions are only derived from the forces of which matter is the vehicle. . . . In fact, instead of matter (as some affirm) being the object of our immediate cognizance, and the laws of matter our most certain form of knowledge, there seems valid ground for the assertion that our notion of matter is a conception of the intellect, force being that externality of which we have the most direct-perhaps even the only direct-cognizance. . . Mind, like force, is essentially active, all its states are states of change; and of these changes we become directly or immediately conscious by our own experience. . . . Now nothing can be more certain than that the primary form of mental activity,-sensational consciousness,—is excited through physiological instrumentality. . . . In what way the physical change . . translated into psychical change . we know nothing whatever. There is just the same evidence of what has been termed correlation, between nerve-force and that primary state of mental activity which we call sensation, that there is between light and nerve-force:-each antecedent, when the physiological mechanism is in working order being invariably followed by its corresponding consequent. Each kind of mental activity-sensational, instinctive, emotional, ideational, and volitional—may express itself in bodily movement; and it is clear that every such movement is called forth by an active state of a certain part of the brain, which excites a corresponding activity in the motor nerves issuing from it, whereby particular muscles are called into contraction. No physiologist can doubt that the mechanical force exerted by the muscles is the expression of certain chemical changes which take place between their own substance and the oxygenized blood that circulates through them; or that the nerve-force which calls forth these changes, is intimately related to electricity and other physical forces. . . . That mental antecedents call forth physical consequents, is just as certain as that physical antecedents can call forth mental consequents; and thus the correlation between mind-force