166 FBDEBAL BBPOETBB. �raving mania, or absolute imbecility, in which all exercise of reason is wanting, and there is no recognition of persons or things, or their relations. �But there is a debatable border-line between the sane and the insane, and there is often great difficulty in determining on wbich side of it a party is to be placed. There are cases in whicb a man's mental faculties generally seem to be in full vigor, but on some one subject he seems to be deranged. He is possessed, perhaps, with a belief which every one recognizes as absurd, which he has not rea- soned himself into, and cannot be reasoned out of, which we call an insane delusion, or he has, in addition, some morbid propensity, seem- ingly in harsh discord with the rest of bis intellectual and moral nature. �These are cases of what, for want of a better term, is called partial insanity. �Sometimes its existence, and at other times its limita, are doubtful and undefinable. And it is in these cases that the difficulty arises of determining whether the patient has passed the line of moral or legal accountability for bis actions. �You must bear in mind that a man does not become irresponsible by the mere fact of being partially insane. Such a man does not take leave of bis passions by becoming insane, and may retain as much control over them as in health. He may commit offences, too, with which his infirmity has nothing to do. He may be sane as to his crime, understand its nature, and be governed by the same motives in regard to it as other people ; while on some other subject, having no relation to it whatever, he may be subject to some delusion. In a reported case, a defendant was convicted of cbeating by false pretences, but was not saved from punishment by his insane delusion that he was the lawful son of a well-known prince. The first thing, therefore, to be impressed upon you is, that wherever this partial insanity is relied on as a defenee, it must appear that the crime charged was the product of the delusion, or other morbid condition, and connected with it as effect with cause, and not the resuit of sane reasoning or natural motives, which the party may be capable of, not- withstandihg his circumscribed disorder. The importance of this will be appreciated by you further on. �But, assuming that the infirmity of mind has had a direct influence in the production of crime, the difficulty is to fix the degree and char- aeter of the disorder which, in such case, will create irresponsibility in law. The outgivings of the judicial mind on this subject have not ��� �
