son-considered it reason-but reason of a lower grade than that which distinguishes the human species of a proper age from mere brute animals. It has generally been defined to be the power which deterinines the will of brutes; or a desire or aversion acting in the mind without the intervention of reason or deliberation. While instinct has been considered a power which has been exerted without reflection, and as belonging mostly to brutes, reason has been considered the power by which we deduce one proposition from another, and as confined altogether to the human species. Brutes, by most philosophers, have been considered as actuated by nothing but instinct, and even the human species as actuated by no other principle in their infantile state.

Descartes and others after him, supposed that brutes were mere mechanical machines, having neither ideas nor sensation; pleasure nor pain; and that their cries and moanings under punishment, and adversity, when moved by an opposite impulse, are produced by the same sort of force, which when exerted upon the keys of an organ compels its respective pipes to give forth different sounds. Dr. Reid of modern times has espoused the doctrine of a mechanical principle, but differs from Descartes in supposing that the actions which are resolvable into this principle are of two kinds, those of instinct and those of habit.

Smellie and Dr. Darwin are in exact opposition to a mechanical force to a corporeal hypothesis. They contend that instinct is a mental principle, and that brutes possess an intelligent faculty of the same nature, though more limited in its extent, than that of our own species. They are agreed in supposing that instinct is a mental effort, and therefore a faculty of reason, but differ by the former supposing that reason is the result of instinct, and the latter that instinct is the result of reason. Darwin recites many instances, with how much propriety those who read may judge, to show that the faculty which has been denominated instinct is in reality reason. An idea of his opinion, in general, may be inferred from the two following extracts from his Zoonomy. "By a due attention to these circumstances, many of the actions, which at first sight seemed only referable to an inexplicable instinct, will appear to have been acquired, like all other animal actions that are attended with consciousness, by repeated efforts of our muscles under the conduct of our sensations and desires." "If it should be asked what induces a bird to

sit weeks on its first eggs unconscious that a brood of young ones will be the product? The answer will be that, it is the same passion that induces the human mother to hold her offspring whole nights and days in her arms, and press it to her bosom, unconscious of its future growth to sense and manhood, till observation or tradition have informed her."

Another set of philosophers have contended that instincts are of a mixed kind, holding an intermediate station between matter and mind; or that in some instances they are simply material, and in others simply mental. Cudworth, at the head of one division of these, from an attachment to the Platonic theory of the creation, an important principle of which is, that "incorporeal form," or " an active and plastic nature," exists throughout its wide domain, independently of pure mind and pure matter, supposed that instinct might be resolved into the operation of this secondary energy, in proportion to its existence in the universe. M. Buffon at the head of the second division of this class, not willing to accede altogether to the mechanical theory of Descartes, or to allot to animals below the rank of man the possession of an intelligent principle, permitted them to be possessed of the principle of life, and allowed them the faculty of distinguishing between pleasure and pain, with the possession of a desire for the former and an aversion for the latter. M. Reimen, a German professor, differing in some measure from this theory; divides the actions which he believes ought to pass under the name of instinct into three classes, mechanical, representative and spontaneous. Mechanical, he considers those actions of animal organs over which the will has no control, as the pulsations of the heart, the secretion of the bile, pancreatic juice, etc., and the dilatation of the pupil of the eye; representative, those which depend upon an imperfect memory, of which brutes are allowed to share in some small degree; and spontaneous, those which originate from M. Buffon's admitted faculty of distinguishing (in the brute creation) pleasure from pain, and the desire resulting from this distinguishing propensity of possessing the one and being freed from the other.

The great Cuvier supposes that instinct consists of ideas which do not originate from sensation, but which flow immediately from the brain and which are truly innate. "The understanding," says he "may have ideas without the aid of the senses; two thirds of the brute creation are moved by ideas which they do not owe to their sensations, but which flow immediately

from the brain.

Instinct constitutes this order of phenomena; it is composed of ideas truly innate, in which the senses have never had the smallest share."

A person who has attended to all these theories, and to all which has ever been written or said upon the subject, is but little wiser than when he commenced his investigations. Some of them, even those of men of great eminence in other respects, are too absurd not to be considered so by men of ordinary abilities. The most inconsistent theories are those which consider animals in the scale of beings next below man, to be mere machines, and to be moved by a mere mechanical impulse. Several other theories which have been mentioned are made up of a collection of inconsistencies, and unintelligible absurdities; and a person attains no knowledge from attending to them. To obviate all the difficulty, and to give place to a theory upon a more rational hypothesis, M. Dupont of Nemours, France, in an article read before the National Institute, proposes to drop the term altogether, and further insists that there is no such thing as instinct; and that every action which has been referred to such a faculty, originates from intelligence, thought, example, or from the association of ideas. This, it will be perceived, is a revival in a new form, of the theory of Smellie and Darwin.

Dr. Good, in his Book of Nature, which we have called considerably to our aid, after taking a general survey of the opinions and theories of other philosophers, comes to the conclusion that the principle of instinct never has been explicitly pointed out. After a few preliminary observations, he proposes to exhibit a new view, or a new theory upon the subject. He directs the attention to inorganic matter, which he has previously extensively spoken of; particularly to some of the more prominent characters by which this is distinguished from organic matter, as a stone from a plant or an animal. The stone, he says, was produced fortuitously, formed by external accretion, and is only destructible by mechanical or chemical agencies. The plant, he observes, is produced by generation, brought forward in its growth by nutrition and by internal accretion, and rendered destructible by death. Animals differ from plants in a number of respects, but they are both characterized by a property which he terms the principle of life. "Life," says he, "or this mysterious or fugitive essence is a distinct principle from that of thought, and from that of sensation. Mr. John Hunter has traced it to many of the organized fluids as well as the

In every organized system,

solids, especially to the blood. whether animal or vegetable, and in every part of such system, whether solid or fluid, may be traced that power, which with such propriety may be denominated the principle of life. Of its cause and nature we know no more than we know of the cause and nature of magnetism. It is neither essential mind, nor essential matter; it is neither passion nor sensation; though it is distinct from all these, it is capable of combining with any of them. It is possessed of its own book of laws, to which, under the same circumstances, it adheres without the smallest deviation.

The agency by which it operates, he says, is what should be denominated instinct, and its actions, when its sole and uniform aim is accomplished, instinctive actions. Instinct, whenever manifestly directing its operations to the health, preservation and reproduction of the living frame, or any part of the living frame, is the operation of the living principle. It is that power which characterizes and distinguishes organized from unorganized matter-pervades and regulates the former as gravitation pervades the latter, uniformly operating by definitive means in definitive circumstances, to the general welfare of the individual system on its separate organs; advances them to perfection, preserves them in it, or lays the foundation for their reproduction as the case may be.

It applies, according to the same theorist, equally to plants and to animals, and to every part of the plant and to every part of the animal, as long as the principle of life continues in them. It maintains from age to age the distinctive characters of plants and animals, carries off the waste or worn out matter, and supsplies new-very often suggests the mode of cure when diseases and injuries have occurred or been inflicted, and even effects the cure itself. "It is," continues he, "the divinity that stirs within us, and is the much noted vis medicatrix naturae,' of so many noted physicians.'

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This is giving it an application so much more extensive than we have been accustomed to think it entitled to and as applied to it, and is linking and classifying actions together, so widely deviating from each other, especially in appearance, that we can with difficulty, even when we can conceive of nothing more plausible, persuade ourselves to afford it our assent. Instinct has generally, if we have not entertained wrong conceptions, been supposed to comprehend those actions only, which seemed

to arise, whether in the new born infant or in brute animals, from a voluntary motion. Such are the acts of the infant, when from some cause or other, it seeks nutriment from its mother's breast; such are the acts of all the mammiferous animals in the same circumstances, the seeming anxiety of these to take care and preserve their young, with a great many other similar acts; such are the actions of the feathered tribes to sit for weeks upon their eggs until they are hatched, and then to feed and brood over them until they are capable of taking care of themselves; and such are a thousand acts of a similar kind in other animals, which it is unnecessary in this place to particularize.

With proper deference to a character so esteemed as a physician, so much admired as a professor, and so noted as an author, I shall venture to deviate from the above mentioned theorist, and prescribe narrower limits to the actions of instinct, and in some respects ascribe them to different faculties than those to which they have been usually considered as belonging.

To impart clear views, I shall follow still further the theory of Dr. Good, and afterwards commence the examination of the one just mentioned. At the conclusion of the first lecture of Dr. Good, he says that "instinct may be defined the operation of the principle of organized life by the exercise of certain natural powers directed to the present or future good of the individual; and reason the operation of the principle of intellectual life, by the exercise of certain acquired powers directed to the same end." Towards the commencement of his other lecture, he says, "Instinct is the common law or property of organized matter, as gravitation is of unorganized; and the former bears the same analogy to sensation and perception that the latter does to crystalization and chemical affinity. Instinct is the general faculty of the organized mass as gravitation is of the unorganized mass; sensation and perception are peculiar powers or faculties appertaining to the second; they can only exist under certain circumstances of the organized or unorganized matter to which they respectively belong. Gravitation belongs equally to the smallest portions of unorganized matter; instinct in like manner belongs equally to the smallest portions of organized matter; it exists alike in solids and fluids; in the whole frame, and in every part of the frame; in every organ and in every part of every organ, so long as the principle of life continues." There might be some beauty, at least, and some propriety in such a theory, if the mind had not restricted it to narrower limits.