It would be a curious and instructive enquiry to ascertain under what circumstances the mind admits as rules for action, those principles which do not admit of proof: because, if we could detect the manner in which the knot is tied, we might probably be able to unloose it. In the course of our education we are taught to adopt many maxims, the truth and expediency of which may not be very evident; however as we advance in life, experience and good sense gradually dispel many of these prejudices and erroneous adoptions. But in the insane mind the same process does not take place, and generally in proportion to the reasoning adduced to confute the delusion, or the demonstration employed to exhibit its absurdity, it becomes more strongly confirmed and inveterately fixed; and the logic brought forward for its refutation, is by the lunatic held as ignorance or misapplication. A person _in_ his senses may entertain and believe a number of unfounded and erroneous opinions, but on the exposure of their falsity he is capable of being convinced, but the madman never is; and this forms the great distinction between them. This incapability of being convinced of the GOOD and EVIL, RIGHT and WRONG, TRUTH and FALSHOOD of his BELIEF is that, which as an intellectual being, renders him different from other men, and constitutes his distemper. To our present purpose, it is immaterial how this arises, the knowledge of its existence is sufficient: and it concerns us but little to ascertain if this state depend on a morbid condition of the intellect itself, or of the organ destined for the display of its phenomena.