MATERIAL INFLUENCES ON MENTAL OPERATIONS.

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a particular texture and temperament of the material frame, and a corresponding quality of the vital fluids, should be possessed, in conjunction with the former. Our material and medial constitution should, moreover, be so ordered, that they will completely harmonize and co-operate with the higher part of the system.

Another subject of considerable importance consequent on the foregoing considerations, is the inquiry to what extent, and in what respects, the various intellectual faculties and capacities are influenced by the constitution and condition of the material frame, and its different organs and members.

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It does not seem probable, nor can we reasonably suppose, that any of these faculties or capacities are at all dependent upon the body, or upon any part of it, either for their actual existence, or for the extent to which they may respectively be found; or for the powers or qualities with which they may be endowed: or that these peculiar characteristics are, any of them, affected or altered by the constitution or condition of the corporeal frame. On the other hand, it does appear that these various faculties and capacities, and also certain qualities relating to them, are very greatly dependent upon the particular nature and constitution of the material frame, and its organs; and also on its texture, temperament, and fluids, both for their vigour in operation, and for the facility and alacrity with which they carry on their several actions. Thus, a vast difference is perceptible owing to this, not only between different persons, but in the same person at different periods of his life and growth, according as his frame changes; and even at various periods of the same day, as that frame is languid or vigorous." And if we find that the several characteristics of the different faculties and capacities change, in exact correspondence with these bodily changes; can we, without some very powerful and adequate cause for so doing, doubt of the intimate connexion between, and of the essential dependence of the one upon the other?

The exercise of this influence by the material frame over the intellectual faculties, is not however always uniform in its operations. Thus, that particular condition of the body which by its exhilarated state will heighten the flow of invention, and stimulate

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Sir W. Lawrence lays it down that "the differences between man and animals, in propensities, feelings, and intellectual faculties, are merely the result of a difference in organization."-Nat. Hist. of Man, s. i. c. vii. 4 Mr. Smee considers that even the mental faculties arise from the organization of the nervous system."-Instinct and Reason, p. 311. Dr. Richardson, remarks with regard to this passage :you take respecting the condition of the body as affecting the mind, I agree with you. You seem to me to place the positions fairly and fully. Your observation on night and morning work is most true."

On the view

the exuberance of wit, will greatly impede the exercise of each of the reasoning capacities, and of those of understanding also. The mind is most active and volatile when the spirits are high, as is generally the case in a morning; and it is then capable of the most vigorous efforts. But it is when the spirits are more depressed, as in the afternoon part of the day, that the action of the mind is easiest to control, and the readiest to obey the discipline to which it has been subjected. For original conception and energetic exertion, the former condition is the most favourable; although for deep reflection and earnest continuous application, the latter is the best fitted. student at sunrise, enunciates the most brilliant ideas. But the student by lamplight, produces thoughts which are the most mellowed and well digested.

The

It does not, however, appear to me, so far as I can judge from my own observation, and from internal reflection, that the condition of the body in any degree either extends or limits the actual power of the mind. The real essential result of bodily disorder, or defect of this description, is that it greatly affects the ease with which the organs of the body obey the impulses of the mind, and are able to act in any intellectual operation for which they are required. The mind and the body are ever distinct and independent, although so closely conjoined. Thus, a horse harnessed to a carriage, is exactly the same animal, and undergoes no change, whether the carriage is empty or whether it is overloaded, although his movements are far more agile and easy in the former case than in the latter."

Nevertheless, when we consider the vast variety of substances, of which our bodies are made up, and the diversity of organs employed in our intellectual operations; when we reflect on the numerous properties and constituents appertaining to each of these subjects, flesh, blood, nerves, sinews, gastric juice, vital fluids of different kinds, and the like, each of which varies in different persons, and in the same person at different periods; when we remember, moreover, how each of these sub

The following note by Mr. Serjeant Cox has been contributed on this passage:-"I cannot assent to this view of the exemption of the mind from the influence of the body. The individual Ego holds communication with the external world through the medium of the material mechanism of the brain. The resulting action of the brain is what we call the mind. The soul (or self) is the conscious thing that receives the impressions of brain action. If the body is in an unhealthy condition, the brain usually partakes of that condition, and its action is either deadened or disordered. When the body is weary, the mind in its normal state is wearied also,* as is shown by the difficulty we feel in thinking, or following any other mental action. This is one instance only; but they appear to me to be innumerable. What is insanity itself but disordered brain action ?"

* Vide ante, Prel. Diss., vol. i. s. vii. a. 1.

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jects is liable to be affected by the temperature and pressure of the atmosphere, and numerous external causes, some of which are ever in operation; we cannot but be convinced that the condition of the body must necessarily exercise a very considerable influence over the mind, especially as regards its activity, and adaptation for exertion."

That the higher the intellectual faculties and capacities are, the more independent they are of the body, is well evinced by the state and operation of the mind during sleep, when it acts altogether uncontrolled by the material frame, from which it becomes for the time disconnected. Thus, at this period, the faculty of understanding, which is the most allied to, and dependent on, the body, as through the senses alone all ideas are received into the mind, is in a state of entire inactivity, although while we are awake it is almost ceaselessly active. Reason is occa

sionally, though not frequently, and but seldom to a very great extent, exercised when we are in this condition. Genius, especially the imaginative capacity, that of origination, which is the highest, is during this period very fully and very constantly exerted. Wit, being dependent for its operation on the communication of new ideas by the aid of the understanding, is probably then less active than are any of the other capacities of this faculty. And taste, for the same reason, is also limited, it may be to a less extent, in its exercise; although occasionally it is at this period very fully exerted.

We may also observe in old age, when the corporeal organs have decayed, or become enfeebled, that the understanding is that faculty whose activity and vigour appear chiefly to be impeded, from this being the faculty most intimately allied to, and extensively dependent on, the body. That the faculty of reason is that which is in ordinary cases the next to suffer; while the faculty of genius, which is the least dependent on the body, continues in full vigour. Wit-although from there being less abundance of animal spirits humour is not so much exerted at this period is as keen as ever, the taste as refined, and the imagination as powerful.

That the individual nature, and peculiar endowments and qualities of the soul, and not the quality or particular formation of the body, or any of its parts or organs, are nevertheless what determine the actual character of the man; is proved by the fact that whatever changes the latter may undergo, whether in texture, or temperament, or even in general constitution, the same peculiar, intellectual, and moral character remains,

7 Mr. Isaac Taylor, indeed, asserts, that "reason in man is not absolute reason, but a reasoning faculty dependent to a great extent upon, and characterized by, the particular cerebral conformation, and by the constitution or temperament of the individual."-Physical Theory of Another Life, c. v.

modified, indeed, by these changes, so far as its development and exercise are affected by them. Certain faculties may be late in becoming displayed; but when they have once been brought into action, they never cease to exist. The man of extensive genius, or of powerful reasoning, ever possesses through life the same endowments and intellectual character; and although these powers may be modified by age, and various causes, their actual nature remains unchanged. If, on the other hand, the intellectual and moral character of a person depended on his physical formation, this would necessarily alter with his growth. The bodily frame of each individual is very different in youth and in old age, and so also are his habits and pursuits. But his intellectual faculties and capacities, his disposition, and moral character, remain the same, notwithstanding these vast changes; inasmuch as his soul retains unaltered her pristine character, which may indeed be well regarded as an additional and sure proof of her immutable and purely spiritual nature.

10. Growth and Development of the different Faculties and Capacities.

The several faculties of the mind are developed at different periods of the growth of the body, according as the material mental organs attain maturity, or the faculties of the mind are respectively excited to action, and arrive at a state of vigour. The various capacities of these different faculties are also displayed at different periods of age; those of the more ordinary kind, such as apprehension and sense, being of more general utility, arc developed and called into exercise sooner than those of a more exalted nature. Apprehension, indeed, is probably exercised shortly after the individual enters upon his existence, while others may be a long period before they are roused

"The child when he first comes into the world, may care very little for what is passing around him, although he is, of necessity, always learning something even at first; but, after a certain period, he is in a rapid progress of instruction; his curiosity becomes irrepressible; the thirst for knowledge is predominating in his mind, and it is as universal as insatiable. During the period between the ages of eighteen months ortwo years, and six,-I will say even and five,-and he learns much more of the material world,-of his own powers, of the nature of other bodies, even of his mind, and of other minds,-than he ever after acquires during all the years of boyhood, youth, and manhood. Every child, even of the most ordinary capacity, learns more, gains a greater mass of knowledge, and of a more useful kind at this tender age, than the greatest philosopher is enabled to build upon it during the longest life of the most successful investigation,-even were he to live to eighty years of age, and pursue the splendid career of Newton or La Place."-Lord Brougham,

DIFFERENT PERIODS OF MENTAL DEVELOPMENT.

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to exertion. The capacities which constitute reason reach perfection in middle age; while those of genius appear to be most active during youth, but most perfect and vigorous in old age. The capacities of the understanding are most docile during youth. Probably, however, the capacity of deprehension possesses the greatest vigour during middle life, and comprehension at that period, and in old age.

Does this prove that the intellectual faculties and capacities are wholly dependent on the body? Not by any means, inasmuch as reason improves while age advances; which arises, however, not from the material frame having reached maturity, but in consequence of the exercise and experience which this faculty gradually acquires.

So also is it with regard to the capacities which constitute the understanding. Apprehension is certainly most pliable, and ready to receive impressions, during youth. Like a sheet of paper which is but very partially written upon, there then is greater facility for communicating to it new ideas than when it has been covered over with cyphers.

Genius is, perhaps, most apt to be exercised during youth, when the spirits are high, and leisure is afforded for the pursuits in which it aids; but, as I stated before, it often happens, as in the case of Milton and Michael Angelo, that the imagination, and taste, and wit, are even more vigorous in old age than they were during youth.

In children, apprehension, and sense, and wit are principally constituted, simply because these are the capacities which are principally called into action. Mirth prevails most during youth, as we see also among animals, which at that period gambol and frisk about, and appear to be endowed with exquisite humorous qualities.

On the whole, therefore, I believe that youth is the season when the understanding is in its prime; manhood that of reason; and old age that of genius; although the latter faculty is perhaps most frequently exerted during the first period. The whole number, or full extent, of a person's faculties and capacities may possibly not be known even to himself, until he has reached maturity, when he begins to observe the general operations of the world around him, and his abilities and energies are for the first time called forth into active play. And, on the other hand, for the same reason, his

Speech on the Education of the People. Lord Brougham's Speeches, vol. iii. pp. 234, 235.

"The child is distinguished by the quickness of apprehension through the medium of its senses, which decreases from early youth, to extreme old age. In early infancy the child obtains much knowledge of the external world, and remembers before it has any use of language."-The Mind of Man. By Alfred Smee, F.R.S., pp. 34, 35.