The second kind of insanity is called _illusional_ or _delusional_. In it the intellect is not impotent; on the contrary, it is often unusually active; but its action is abnormal, its conclusions are false. Not that it reasons illogically or draws conclusions which are not contained in the premises. Very keen logicians may be demented. Their unsoundness arises from the fact that they reason from false premises; and they get their false premises from their diseased imaginations, whose vagaries they take for realities. 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.