It is a vain question, that which has been often stirred among men of our profession and metaphysicians, whether insanity--including under that word all the modes of derangement of the mental powers--is strictly a _disease_, the definition of which, according to the best authorities, is "an alternation from a perfect state of bodily health." Both parties may, to a certain extent, be right; for the one, including chiefly the metaphysicians, can successfully exhibit a gradation in the scale of derangement: beginning at the slightest peculiarity; passing on to an eccentricity; from that to idiosyncrasy; from that to a decay or an extraordinary increase of strength in a particular faculty--say memory; from that to a decay or an increase in the intensity of a feeling, an emotion, or a passion; from that to false perception--such as monomania, progressing to derangement as to one point or subject, often called madness, _quoad hoc_; and so on, through many other changes, almost imperceptible in their differences, to perfect madness--all without the slightest indication of a pathological nature being to be discovered or detected by the finest dissecting-knife. On the other hand, again, it is indisputable--for we medical men have demonstrated the fact--that a certain _degree_ of madness is almost always accompanied with derangement in the cerebral organs--the most ordinary appearance being the existence of a fluid of a certain kind in the chambers of the brain. The best and the cleverest of us must let these questions alone; for, so long as we remain--and that may be, as it likely will be, for ever--ignorant of the subtle principle of organic life--the nature of the mysterious union of mind and matter--we will never be able to tell (notwithstanding all our mental achievements) whether madness has its primary beginning in the body or in the mind. We must remain contented with a knowledge of exciting causes, and with that melancholy lore which treasures up--alas! for how little good!--the dreadful symptoms which distinguish this miserable state of proud man from all other conditions of his earthly sorrow; exhibiting him conscious of being still a human creature impressed with the image of God, yet incapable of using the proudest gift of Heaven--his reason; susceptible of and suffering the most excruciating of all pains--imaginary evils, torments, agonies--yet placed beyond the pale of human sympathy; bent upon--following with cunning and assiduity the cruellest modes of self-immolation; and sometimes calmly _reasoning_ on the nature of the mysterious power that impels to a horrible and revolting suicide.