We must all have observed the promptness with which we avoid any sudden danger, or inconvenience, before we have time to reason about the matter. As, for example, when we stumble, we instantly put forth the proper foot to prevent our fall. This cannot be said to be an act of the reasoning powers, because they have not had time to operate; and it is equally clear that it is not an act of instinct, because infants, who have only begun to walk have not the capacity of doing it. It is evidently another principle which, availing itself of the knowledge which the person has previously acquired by experience, now uses it specially for the occasion.

That this application of our knowledge arises neither from instinct nor from reason, will be obvious from many circumstances of ordinary occurrence.—For example, when any object approaches the eye we instantly shut it;—when any missile is thrown at us, we instantly turn the head aside to evade it;—or when in walking something destroys our equilibrium and we stumble, we instantly bend the body in the proper direction, and to the precise point, necessary to restore our balance, and to prevent our fall.—Now it is obvious, that all these contingencies are provided for by one and the same principle, whatever that principle may be; and that they are acts which do not depend upon instinct, properly so called, is proved from the circumstance, that infants, before they are taught by experience that the eye is so tender, and even adults who have but newly acquired the use of their sight, neither shut their eyes at the approach of objects, nor turn away their heads when a missile is thrown at them.—And we think it is equally clear, that it cannot be the result of reasoning, in the sense in which we generally understand that term, because the mind has no time for consideration, far less for reasoning, during the short moment that occurs between the cause and the effect.

The object which we have chiefly in view at present is, to point out the great end designed by Nature in all these actions, which is simply the application of knowledge. There is the knowledge that objects entering the eye will give pain, and that the shutting of the eye will defend it. This we have shown is not an instinctive operation, but must have been acquired by experience;—and it is this principle, into the nature of which we are now enquiring, that prompted the child in the special case to apply its knowledge by shutting the eye. In like manner, in the case of the missile thrown at the head, there is a previous knowledge of the effect which it will produce, and a knowledge also of the means by which it is to be avoided,—and it is avoided;—and in the case of losing the equilibrium, there is nothing more than the application of a latent knowledge, now suddenly brought into use on the spur of the moment, that by the movement of the foot the body will be supported. The principle, whatever it be, which instigates children and adults to do all this, is the subject of our present enquiry, and which for the present we have denominated the "Animal," or "Common sense." We shall therefore a little more particularly attend to its various indications.

The operation of this principle in the infant has already been pointed out. When it has learned by experience that its nurse is kind, it stretches forth its little hands, and desires to be with the nurse;—when in its first attempt at walking it experiences a fall, it applies this knowledge, by refusing again for some time to walk;—and when it burns its finger at the flame of the candle, the application of that knowledge induces it ever after to avoid both fire and flame.

In after life the same principle continues to operate both independently of reason, and in conjunction with it. In encountering the air of a cold night, we, without reasoning on the matter, wrap ourselves closer in our cloak. When we turn a corner, and meet a sharp frosty wind, we lower the head to protect the uncovered face. When we emerge from the house, and perceive that the dulness of the day indicates rain, we almost instinctively return for a cloak or an umbrella. And the mariner at sunset, when he sees an opening in the sky indicating a storm, immediately takes in sail, and makes all snug for the night. In all these cases we perceive a principle within us, frequently operating along with reason, but sometimes also without it, which prompts us to apply our previous knowledge for our present comfort and advantage.[7] The constant operation of such a principle in our nature, no matter by what name it is called, leads us, as plainly as analogy and natural phenomena can do, to conclude, that it ought to be carefully studied, and assiduously cultivated in the young, during the period usually assigned for their education.

When we carefully trace the operation of this principle in common life, it appears that, in fact, the greater portion of our physical comforts depends upon it. "Experience" is but another name for it. We find some substances warmer, softer, harder, or more workable than others, and we apply this knowledge by substituting one for another. The savage finds the wigwam more convenient, or more easily come at, than a cave or a crevice in a rock, and he builds a wigwam;—he finds a hut more durable than a wigwam, and he substitutes a hut;—he at last finds a cottage still more convenient, and he advances in his desires and his abilities by his former experience, and he builds one.—In every advance, however, it is the application of his previous knowledge that increases his comforts, and tends to perpetuate them; and accordingly, as a proper and a general application of the "moral sense," leads directly to national virtue; so the proper and general application of this principle of "common sense" goes to promote every kind of personal and family comfort, as well as national prosperity. Its ramifications pierce through every design and action of industry and genius. It is the exercise of this principle alone which, in the worldly sense, distinguishes the wise man from the fool; and which gives all the superiority which is possessed by a civilized, over a savage community. It is the chief guardian of our safety, and the parent of every personal and domestic comfort. It is, in short, familiarity with its exercise that imparts confidence to the philosopher, decision to the legislator, dexterity to the artificer, and perfection to the artist. In each case it is the accumulation of knowledge put to use, which makes the distinction between one man and another; and it is by the aggregation of such men that a nation becomes prosperous. It must never therefore be forgotten, that it is not the possession of knowledge, but the use which we make of it, that confers distinction. For no truism is more incontrovertible than this, that knowledge which we cannot or do not use, is really useless.

There is no wonder then that Nature should be at some pains in training her pupils to an exercise on which so much of their happiness and safety depends; and it is of corresponding importance, that we should investigate the means, and the mode by which she usually accomplishes her end. If we can successfully attain this knowledge, we may be enabled to pursue a similar course in the training of the young, and with decided advantage.

When we take any one of the numerous examples of the working of this principle in the adult, and carefully analyze it, we can detect three distinct stages in the operation, before the effect is produced. The first is the knowledge of some useful truth, present to the mind, and at the command of the will;—there is, secondly, an inference drawn from that truth, or portion of our knowledge, or the impression of an inference which was formerly drawn from it, and which, as we have seen in the infant, may remain long after the circumstance from which the lesson was derived has been forgotten;—and there is, thirdly, a special application of that inference or impression to our present circumstances. For example, in the case of the person leaving the house, and suddenly returning to provide himself with an umbrella, there is first the knowledge of a fact, that "the sky is lowering;" then there is an inference drawn from this fact, that "there will most probably be rain;" but the comfort—the whole benefit arising from this knowledge, and from this reasoning upon it,—depends on the third stage of the operation, which is therefore the most important of all, namely, the application of the inference, or lesson, to his present circumstances. A mere knowledge of the fact that the sky lowered, would have remained a barren and a useless truth in the mind, unless he had proceeded to draw the proper inference from it; and the inference itself, after it was drawn, would have done him no good, but must rather have added to his uneasiness, had he not proceeded to the third step of the operation, and applied the whole to the regulation of his conduct, in providing himself with an umbrella or a cloak.

In like manner, in the supposed case of the mariner expecting a storm, there was first the knowledge of the fact, that the "sky was in a certain state." Now of this knowledge every person on board might have been in possession as well as the master himself, without the slightest benefit accruing to themselves or the ship, unless they had been trained, or enabled to draw the proper inference or lesson from it. The mere possession of the knowledge, therefore, would have been of no advantage. But the practised eye, and the previous experience of the master, enabled him to draw the inference, that "there will be a storm." Even this, however, would not have saved the ship and crew, without the third, and the most important step of all,—the application of that inference or lesson to their present condition. It was that which induced him to give the necessary orders to prepare for the storm, and thus to secure the safety both of the ship and of all on board.

Again, in the case of the infant burning its finger, there appears to be something like a similar process, which we can trace much better than the child itself. The child puts its finger to the flame of the candle, and it feels pain; from which it learns, for the first time, that flame burns. This is the knowledge which it has acquired. But there is also an inference drawn from that knowledge, not by reasoning, but by the operation of the principle under consideration, an inference of which it is probable the child itself at the time is unconscious, but the existence of which is sufficiently proved by its uniform conduct afterwards. By the operation of this principle in the child's mind, before he can reason, he has inferred, that if he shall again touch flame, he will again feel pain. He will very probably forget the particular circumstance in which his finger was burned, but the inference then drawn,—the impression made upon the mind, and which corresponds to an inference,—still remains, and is made the chief instrument which Nature employs in this most important part of all her valuable educational processes. The child accordingly is found ever after, not only preserving the particular finger that was burned, but all its fingers and members, from a burning candle; and not from a candle only, but from fire and flame of every kind.