'But, although such a being (a purely intellectual being) might perhaps be conceived to exist, and although, in studying our internal frame, it be convenient to treat of our intellectual powers apart from our active propensities, yet, in fact, the two are very intimately, and indeed inseparably, connected in all our mental operations. I already hinted, that, even in our speculative inquiries, the principle of curiosity is necessary to account for the exertion we make; and it is still more obvious that a combination of means to accomplish particular ends presupposes some determination of our nature, which makes the attainment of these ends desirable. Our active propensities, therefore, are the motives which induce us to exert our intellectual powers; and our intellectual powers are the instruments by which we attain the ends recommended to us by our active propensities:

"Reason the card, but passion is the gale."'

DUGALD STEWART, Philosophy of the Active Powers, p. 2.

CHAPTER I.

OF FEELING IN GENERAL.

IND is comprised under the three heads-FEELING,

1. MIND

VOLITION, and INTELLECT.

FEELING includes all our pleasures and pains, and certain modes of excitement, to be afterwards defined, that are neutral as regards pleasure and pain.

Under the Muscular Feelings and the Sensations of the Senses, I reviewed in detail those feelings of a primary character, due, on the one hand, to the putting forth of muscular energy, and, on the other, to the action of the outer world on the organs of sense. There remains a department of secondary, derived, or complicated feelings, termed the Emotions.

2. In my former volume, I adduced facts to prove the dependence of all the mental workings on bodily organs; and, in treating of the sensations, gave in each instance the physical side as well as the mental; all which is applicable to the Emotions.

The most general principle that we are able to lay down respecting the concomitance of mind and body may be called the LAW of DIFFUSION. It is expressed thus: When an impression is accompanied with Feeling, or any kind of consciousness, the aroused currents diffuse themselves freely over the brain, leading to a general agitation of the moving organs, as well as affecting the viscera.'

I may quote, as an illustrative contrast, the so-called Reflex actions (breathing, &c.), which have no feeling, and are operated through a narrow and confined nervous circle.

It is not meant that every fibre of the brain is affected in

the course of the diffusion, but that a spreading wave is produced enough to agitate the collective bodily organs.

The organs first and prominently affected, in the diffused wave of nervous influence, are the moving members, and of these, by preference, the features of the face, whose movements constitute the expression of the countenance. But the influence extends to all the parts of the moving system, voluntary and involuntary; while an important series of effects are produced on the glands and viscera-the stomach, lungs, heart, kidneys, skin, together with the sexual and mammary organs.

3. The facts that establish the companionship of feeling and diffusive action have been abundantly quoted in the description of the sensations. Each of us knows in our own experience that a sudden shock of feeling is accompanied with movements of the body generally, and with other effects. So well are we convinced of this, that we judge of the intensity of feeling in others by the extent and energy of their manifestations. Sleep is accompanied with stillness of the bodily movements; the waking to consciousness has for its physical side the renewal of the active energies of the system, with a series of changes in the organic functions.

It is well known that impressions fail to produce consciousness, when the mind is strongly pre-engaged. In the heat of a battle, wounds may be for a time unfelt. A person very much engrossed with a subject gives no heed at the moment to words addressed to him, but should his attention be relaxed before the impression fades from the ear, he will probably return an answer.

One of the remedies for pain or uneasiness is to divert the attention and activity, or even the current of the thoughts.

We are able in some degree to restrain the feelings by the power of the will. Now as the will can act only on muscles, it follows that the moving organs must participate in the embodiment of the feelings.

4. This doctrine has an important bearing on the Unity of the Consciousness. A plurality of stimulations of the nerves may co-exist, but they can affect the consciousness

DOCTRINES OPPOSED TO DIFFUSION.

5

only by turns, or one at a time. The reason is that the bodily organs are collectively engaged with each distinct conscious state, and they cannot be doing two things at the same instant. The eyes cannot minister to one feeling, the ears to another, and the hands to a third; for, although the feeling may not be strong enough to involve the activity of all the organs, yet those unemployed must either be at rest or engaged in mere routine functions, such as walking, that are not necessarily accompanied by consciousness.

5. The counter-doctrines to the theory of Diffusion are the following:

First. It may be maintained that the mind is not dependeut on bodily processes throughout. Admitting that there is an occasional accompaniment of outward agitation with inward feelings, one may hold that this is merely casual and incidental, and not at all essential to the existence of the feelings. It may be said that, although certain energetic emotions have bodily manifestations, a great many feelings rise up without affecting any bodily organ. Some of our emotions, it may be contended, are of so tranquil a nature as to have only a pure mental existence, and produce no disturbance in any part of the physical system.

It is here maintained, on the contrary, that no feeling, however tranquil, is possible without a full participation of the physical system; the apparent tranquillity merely signifying that the diffused wave is too feeble to produce observable effects.

Secondly. The uniform connexion of mental states with. bodily conditions may be admitted, but with the supposition that one or other of the ganglia, or lesser grey centres of the brain, is all that is necessary to sensation. The corpora quadrigemina have been called the ganglion of the sense of sight, as the olfactory bulb is the ganglion of smell; and it has been supposed that these are enough for mere sensation. I, on the contrary, am disposed to maintain that the hemispheres are requisite to consciousness in every shape; and that these hemispheres are the medium of the accom

panying diffusion of stimulus to the collective system of muscles and glands.

Thirdly. It is not uncommon with those that fully believe in the participation of the brain in every mental experience, to restrict it to the brain. To this view, I oppose the doctrine of the farther participation of the outcarrying nerves, the muscles, and the viscera. If we suppose, for example, that a shock of Fear could be prevented from actuating the moving organs, the stomach, the skin, the heart, or any other organ usually affected, our mental experience would not be what is characteristic of the emotion.

6. The theory of Reflex, or Automatic, actions is in strict. accordance with the view now taken of the physical accompaniments of feeling or consciousness. These automatic actions, such as the movements of the heart and lungs, the movements of the intestines, &c., are proved to depend upon the spinal cord and medulla oblongata, to the exclusion of the cerebral hemispheres. A reflex action is an isolated response from some one single centre, or some limited portion of grey matter, and not a diffused influence over the system at large. With such local restrictions is associated the property of unconsciousness, or want of feeling, attaching to this class of actions.

7. The Habitual, or routine, actions, which make up the acquired ability and skill of men and animals, have sometimes been termed 'secondarily automatic.' The reason is that they resemble in a great degree the actions just alluded to, the reflex, or primary automatic. They are performed almost unconsciously; that is to say, the more thoroughly they attain the character of routine, or habit, the less is the feeling that attends their exercise. Such actions as walking, turning a wheel, stitching, may be sustained without giving rise to any but a feeble conscious impression, so as to leave the mind free for other exercises or emotions. Now, the only view that we can take of the physical machinery of those actions, is to suppose that the originally diffused wave that accompanied them has become contracted within some narrow circles of the brain,