It is from Nature—from his parents—from causes, which from the first moment of his existence have unceasingly modified him, that man derives his temperament. It is in his mother's womb that he has attracted the matter which, during his whole life, shall have an influence on his intellectual faculties—on his energies—on his passions—on his conduct. The very nourishment he takes, the quality of the air he respires, the climate he inhabits, the education he receives, the ideas that are presented to him, the opinions he imbibes, modify this temperament. As these circumstances can never be rigorously the same in every point for any two men, it is by no means surprising that such an amazing variety, so great a contrariety, should be found in man; or that there should exist as many different temperaments, as there are individuals in the human species.
Thus, although man may bear a general resemblance, he differs essentially, as well by the texture of his fibres and the disposition of his nerves, as by the nature, the quality, the quantity of matter that gives them play, that sets his organs in motion. Man, already different from his fellow, by the elasticity of his fibres, the tension of his nerves, becomes still more distinguished by a variety of other circumstances: he is more active, more robust, when he receives nourishing aliments, when he drinks wine, when he takes exercise: whilst another, who drinks nothing but water, who takes less juicy nourishment, who languishes in idleness, shall be sluggish and feeble.
All these causes have necessarily an influence on the mind, on the passions, on the will; in a word, on what are called the intellectual faculties. Thus, it may be observed, that a man of a sanguine constitution, is commonly lively, ingenious, full of imagination, passionate, voluptuous, enterprising; whilst the phlegmatic man is dull, of a heavy understanding, slow of conception, inactive, difficult to be moved, pusillanimous, without imagination, or possessing it in a less lively degree, incapable of taking any strong measures, or of willing resolutely.
If experience was consulted, in the room of prejudice, the physician would collect from morals, the key to the human heart: in curing the body, he would sometimes be assured of curing the mind. Man, in making a spiritual substance of his soul, has contented himself with administering to it spiritual remedies, which either have no influence over his temperament, or do it an injury. The doctrine of the spirituality of the soul has rendered morals a conjectural science, that does not furnish a knowledge of the true motives which ought to be put in activity, in order to influence man to his welfare. If, calling experience to his assistance, man sought out the elements which form the basis of his temperament, or of the greater number of the individuals composing a nation, he would then discover what would be most proper for him,—that which could be most convenient to his mode of existence—which could most conduce to his true interest—what laws would be necessary to his happiness—what institutions would be most useful for him—what regulations would be most beneficial. In short, morals and politics would be equally enabled to draw from materialism, advantages which the dogma of spirituality can never supply, of which it even precludes the idea. Man will ever remain a mystery, to those who shall obstinately persist in viewing him with eyes prepossessed by metaphysics; he will always be an enigma to those who shall pertinaciously attribute his actions to a principle, of which it is impossible to form to themselves any distinct idea. When man shall be seriously inclined to understand himself, let him sedulously endeavour to discover the matter that enters into his combination, which constitutes his temperament; these discoveries will furnish him with the clue to the nature of his desires, to the quality of his passions, to the bent of his inclinations—will enable him to foresee his conduct on given occasions—will indicate the remedies that may be successfully employed to correct the defects of a vicious organization, of a temperament, as injurious to himself as to the society of which he is a member.
Indeed, it is not to be doubted that man's temperament is capable of being corrected, of being modified, of being changed, by causes as physical as the matter of which it is constituted. We are all in some measure capable of forming our own temperament: a man of a sanguine constitution, by taking less juicy nourishment, by abating its quantity, by abstaining from strong liquor, &c. may achieve the correction of the nature, the quality, the quantity, the tendency, the motion of the fluids, which predominate in his machine. A bilious man, or one who is melancholy, may, by the aid of certain remedies, diminish the mass of this bilious fluid; he may correct the blemish of his humours, by the assistance of exercise; he may dissipate his gloom, by the gaiety which results from increased motion. An European transplanted into Hindostan, will, by degrees, become quite a different man in his humours, in his ideas, in his temperament, in his character.
Although but few experiments have been made with a view to learn what constitutes the temperament of man, there are still enough if he would but deign to make use of them—if he would vouchsafe to apply to useful purposes the little experience he has gleaned. It would appear, speaking generally, that the igneous principle which chemists designate under the name of phlogiston, or inflammable matter, is that which in man yields him the most active life, furnishes him with the greatest energy, affords the greatest mobility to his frame, supplies the greatest spring to his organs, gives the greatest elasticity to his fibres, the greatest tension to his nerves, the greatest rapidity to his fluids. From these causes, which are entirely material, commonly result the dispositions or faculties called sensibility, wit, imagination, genius, vivacity, &c. which give the tone to the passions, to the will, to the moral actions of man. In this sense, it is with great justice we apply the expressions, 'warmth of soul,' 'ardency of imagination,' 'fire of genius,' &c.
It is this fiery element, diffused unequally, distributed in various proportions through the beings of the human species, that sets man in motion, gives him activity, supplies him with animal heat, and which, if we may be allowed the expression, renders him more or less alive. This igneous matter, so active, so subtle, dissipates itself with great facility, then requires to be reinstated in his system by means of aliments that contain it, which thereby become proper to restore his machine, to lend new warmth to the brain, to furnish it with the elasticity requisite to the performance of those functions which are called intellectual. It is this ardent matter contained in wine, in strong liquor, that gives to the most torpid, to the dullest, to the most sluggish man, a vivacity of which, without it, he would be incapable—which urges even the coward on to battle. When this fiery element is too abundant in man, whilst he is labouring under certain diseases, it plunges him into delirium; when it is in too weak or in too small a quantity, he swoons, he sinks to the earth. This igneous matter diminishes in his old age—it totally dissipates at his death. It would not be unreasonable to suppose, that what physicians call the nervous fluid, which so promptly gives notice to the brain of all that happens to the body, is nothing more than electric matter; that the various proportions of this matter diffused through his system, is the cause of that great diversity to be discovered in the human being, and in the faculties he possesses.
If the intellectual faculties of man, or his moral qualities, be examined according to the principles here laid down, the conviction must be complete that they are to be attributed to material causes, which have an influence more or less marked, either transitory or durable, over his peculiar organization. But where does he derive this organization, except it be from the parents from whom he receives the elements of a machine necessarily analogous to their own? From whence does he derive the greater or less quantity of igneous matter, or vivifying heat, that decides upon, that gives the tone to his mental qualities? It is from the mother who bore him in her womb, who has communicated to him a portion of that fire with which she was herself animated, which circulated through her veins with her blood;—it is from the aliments that have nourished him,—it is from the climate he inhabits,—it is from the atmosphere that surrounds: all these causes have an influence over his fluids, over his solids, and decide on his natural dispositions. In examining these dispositions, from whence his faculties depend, it will ever be found, that they are corporeal, that they are material.
The most prominent of these dispositions in man, is that physical sensibility from which flows all his intellectual or moral qualities. To feel, according to what has been said, is to receive an impulse, to be moved, to have a consciousness of the changes operated on his system. To have sensibility is nothing more than to be so constituted as to feel promptly, and in a very lively manner, the impressions of those objects which act upon him. A sensible soul is only man's brain, disposed in a mode to receive the motion communicated to it with facility, to re-act with promptness, by giving an instantaneous impulse to the organs. Thus the man is called sensible, whom the sight of the distressed, the contemplation of the unhappy, the recital of a melancholy tale, the witnessing of an afflicting catastrophe, or the idea of a dreadful spectacle, touches in so lively a manner as to enable the brain to give play to his lachrymal organs, which cause him to shed tears; a sign by which we recognize the effect of great grief, of extreme anguish in the human being. The man in whom musical sounds excite a degree of pleasure, or produce very remarkable effects, is said to have a sensible or a fine ear. In short, when it is perceived that eloquence—the beauty of the arts—the various objects that strike his senses, excite in him very lively emotions, he is said to possess a soul full of sensibility.
Wit, is a consequence of this physical sensibility; indeed, wit is nothing more than the facility which some beings, of the human species possess, of seizing with promptitude, of developing with quickness, a whole, with its different relations to other objects. Genius, is the facility with which some men comprehend this whole, and its various relations when they are difficult to be known, but useful to forward great and mighty projects. Wit may be compared to a piercing eye which perceives things quickly. Genius is an eye that comprehends at one view, all the points of an extended horizon: or what the French term coup d'oeil. True wit is that which perceives objects with their relations such as they really are. False wit is that which catches at relations, which do not apply to the object, or which arises from some blemish in the organization. True wit resembles the direction on a hand-post.