2. Here a difficulty presents itself, which we must explain at once, namely, how can there be unsoundness of mind at all? Is not the intellect of man a simple power, and his soul a simple being? How can a simple being become deranged? Can that which has no parts become disarranged, disorganized? I answer, the soul is a simple being, its intellect is a spiritual faculty; and therefore we never say that the soul is insane, nor should we say that the intellect is insane or diseased; but we say that the mind is deranged or insane; the mind comprises more than the intellect; it designates the intellect together with those lower powers that supply the materials for our thought, the chief of which is the imagination. Now the imagination is an organic faculty: it works in and by a bodily organism, which is the brain. Therefore, when the brain is not in a normal condition, the action of the imagination may be disordered. And the intellect or understanding of the spiritual soul is so closely united in its action and its very being with the organic body that the two ever act conjointly, like the two wheels of a vehicle. If one wheel breaks down, the other is thrown out of gear. Thus it is readily understood that mental unsoundness is an affection of the brain, a bodily disease, which may often be relieved and even cured by bodily remedies, by the use of drugs or wholesome food, healthy exercise, fresh air, and all that benefits the nervous system.
Pathologically considered, the nerves may be too excited or too sluggish and torpid; and we have as the result two subdivisions of mental insanity—mania and melancholia. The differences between these two are very striking; as they proceed from opposite causes they produce opposite effects, and, therefore, they betray themselves by very different manifestations; but in one point the two agree, and with this point precisely we are concerned, because in it lies the essence of mental insanity, namely, that both produce a disordered action of the imagination.
3. The manner in which the imagination co-operates in mental action is this. It presents to the intellect the materials from which that power forms its ideas. When we see, feel, hear, taste, or smell anything by our bodily senses, our imagination takes note of the object perceived by forming a brain-picture of it which is called a phantasm. I do not mean to say that it forms a photographic picture of the object; for there can be no photographing taste or smell or feeling; but it forms an image of some kind which it presents to the intellect. This power at once proceeds to form, not a brain-picture, but an intellectual or abstract image of the object presented. For instance, you see this book, and at once you, in some mysterious way which has never yet been explained, impress some image of it on your brain. That you do so is clear from the fact that the image remains when the book is withdrawn. That material image or brain-picture is the phantasm. It is not an idea, though it is often improperly so called. But your intellect forms to itself an idea of a book; that is, you know what is meant by a book. You distinguish between the mere form of a book and the book itself. Your idea of a book is a universal idea, which stands for any book, no matter of what shape or size. Every phantasm, or brain-picture, is a representation which presents its object as having a definite shape or size, while your idea of a book ignores any shape or size. And yet, when your intellect conceives a book, your imagination will picture some particular form of book. If your brain became so affected by disease as to be unfit for the formation and retention of the proper phantasms, then your intellect either would not work at all or it would work abnormally; your mind would then be insane.
4. Now, in an infant the brain is still too soft and imperfect to form the proper phantasms from which the intellect is to elaborate its ideas. A false school of psychology would say that the infant’s brain cannot yet ideate; but that is incorrect language. No brain can ideate or form ideas; an idea is an intellectual or mind image, not a brain image; it is an abstract and universal image, and matter cannot represent but what is concrete and individual. Only a simple and spiritual being, the rational soul, can form ideas. Nevertheless our soul, in its present state of substantial union with our body, is extrinsically dependent on the body; to form ideas it needs to have the sensible object presented to it by a phantasm or brain-picture. Now, a child born blind and deaf, and thus having its mind, as it were, cut off from communication with the outer world, could scarcely form the necessary phantasms, because the clogged senses could not supply proper materials for them; such a child would, therefore, be apt to remain idiotic. And even in children whose outer senses are sound the brain or the nervous system may be too imperfect to allow of its forming proper phantasms. In this torpor of the mind then consists the first kind of mental unsoundness, that of idiocy, or its milder form imbecility. In old age, and in peculiar diseases, the worn-out system may return to a second childhood, then called dementia or dotage. The existence of such species of insanity is not difficult to discover.
5. The second and more common form of insanity, and that which it is often difficult to discover and pronounce upon with certainty, is that which I have called delusional or illusional. Its characteristic trait, its very essence, lies in this, that the insane man mistakes what he imagines for what is real; and he cannot be made to distinguish between imagination and reality, though the difference is obvious to an intellect in its normal state.
In this connection, it is well to point out a distinction, not always observed, but useful to explain the workings of an insane mind, between illusions, hallucinations, and delusions.
(a) An illusion is properly a deception arising from a mistake in sense-perception; as when a half-drunken man sees two posts where there is only one. He has a picture of the post in each eye, and his brain is too much disturbed to refer the two pictures to the same object. In this case the cause of the mistake is subjective. A mirage offers another instance of a sense-illusion; but in it the cause is objective.
(b) A hallucination is a creation of the fancy mistaken for a reality. The deception may be but momentary, as when Macbeth is stealing on tiptoe to the chamber of his guest to murder him. His mind is disturbed by the imagination of the horrid deed he is about to perpetrate. He thinks he sees a dagger in the air, and he says: “Is this a dagger that I see before me, its handle towards my hand? Come, let me clutch thee. I hold thee not, and yet I see thee still; and on thy dudgeon gouts of blood, which was not so before.” But Macbeth, upon a moment’s reflection, sees it is all imagination. “There’s no such thing,” he exclaims. He is not insane, though deceived for a while.
(c) A delusion, on the contrary, is a permanent deception, whether it results from an illusion or a hallucination, it matters not; as a fact, it almost always originates in hallucinations. The deluded man clings to his imaginings; you cannot talk them out of his head. Such is the case of an inebriate who suffers from mania a potu, or “the horrors;” he sees snakes and demons, he thinks, and persists in his error. Such also is a fixed idea not arrived at by faulty reasoning, but come unbidden and proof against all reasoning and evidence. Thus an insane man may be convinced, solely by his imagination, that he is poisoned or pursued or conspired against.
6. This delusion constitutes the essence of mental insanity, which therefore is often called delusional insanity. It may be chronic, i.e., of long continuance, or it may be temporary, acute. For the time being, the effects are the same. Perhaps any man may, at times, be for a moment thrown off his guard, and mistake a fancy for a reality; this does not constitute lunacy. But when the error is so firmly held in the mind’s grasp that nothing can dislodge it thence, then the mind is deranged in its special sphere of action, which consists in knowing the real from the unreal; the mind is then insane.