SUPPLEMENTARY TOPICS.
CHAPTER I.
INSTINCT.—THE INTELLIGENCE OF THE BRUTE AS DISTINGUISHED FROM THAT OF MAN
Closely connected with the philosophy of human intelligence is the science of instinct, or the intelligence of the brute—a subject of interest not merely in its relations to psychology, but to some other sciences, as natural history, and theology.
We work at a Disadvantage in such Inquiries.—With regard to this matter, it must be confessed, at the outset, that we work, in some respects, in the dark, in our inquiries and speculations concerning it. It lies wholly removed from the sphere of consciousness. We can only observe, compare, and infer, and our conclusions thus derived must be liable, after all, to error. The operations of our own minds we know by the clearest and surest of all sources of knowledge, viz., our own consciousness; the operation of brute intelligence must ever be in great measure unknown and a mystery to us. How far the two resemble each other, and how far they differ, it is not easy to determine, not easy to draw the dividing line, and say where brute intelligence stops and human intelligence begins.
Method proposed.—Let us first define instinct, the term usually applied to denote brute intelligence, and ascertain, if possible, what are its peculiar characteristics; we may then be able to determine wherein it differs from intelligence in man.
Definition.—I understand, by instinct, a law of action, governing and directing the movement of sentient beings—distinct, on the one hand, from the mere blind forces of matter, as attraction, etc., and from reason on the other; a law working to a given end by impulse, yet blindly—the subject not knowing why he thus works; a law innate, inherent in the constitution of the animal, not acquired but transmitted, the origin of which is to be found in the intelligent author of the universe. These I take to be the principal characteristics of that which we term instinct.
Instinct a Law.—It is a law of action. In obedience to it the bee constructs her comb, and the ant her chambers, and the bird her nest; and in obedience to it, the animal, of whatever species, seeks that particular kind of food which is intended and provided for it. These are merely instances of the operation of that law. The uniformity and universality which characterize the operations of this principle, show it to be a law of action, and not a merely casual occurrence.
Works by Impulse.—It is a law working by impulse, not mechanical or automatic, on the one hand, nor yet rational on the other. The impelling or motive force, in the case supposed, is not that of a weight acting upon machinery, or any like mechanical principle, nor yet the reflex action of a nerve when irritated, or the spasmodic action of a muscle. It is not analogous to the influence of gravitation on the purely passive forms of matter. Nor yet is it that higher principle which we term reason in man. The bird constructs her nest as she does, and the bee her cell, in obedience to some blind yet powerful and unfailing impulse of her nature, guiding and directing her movements, prompting to action, and to this specific form of action, with a restless yearning, unsatisfied until the end is accomplished. Yet the creature does not herself understand the law by which she works. The bee does not know that she constructs her comb at that precise angle which will afford the greatest content in the least space, does not know why she constructs it at that precise angle, could give no reason for her procedure, even were she capable of understanding our question. It is not with her a matter of reflection, nor of reason, at all, but merely of blind, unthinking, yet unerring impulse.