[Footnote 106: Coke, _Third Institute_, p. 55.] [Footnote 107: Hume, _Commentaries on the Law of Scotland_, i. 365.] [Footnote 108: Günther, _op. cit._ iii. 256 _sqq._] [Footnote 109: _Ibid._ iii. 255 _sq._] It has been said that a man who acts under the influence of great passion has not, at the time, a full knowledge of the nature and quality of his act, and that {298} the clemency of the law is "a condescension to the frailty of the human frame, to the _furor brevis_, which, while the frenzy lasteth, rendereth the man deaf to the voice of reason."[110] But the main cause for passion extenuating his guilt is not the intellectual disability under which he acts, but the fact that he is carried away by an impulse which is too strong for his will to resist. This is implied in the provision of the law, that "provocation does not extenuate the guilt of homicide unless the person provoked is at the time when he does the act deprived of the power of self-control by the provocation which he has received."[111] [Footnote 110: Foster, _Report of Crown Cases_, p. 315.] [Footnote 111: Stephen, _Digest_, art. 246, p. 188.] That anger has been so generally recognised as an extenuation of guilt is largely due to the fact that the person who provokes it is himself blamable; both morality and law take into consideration the degree of provocation to which the agent was exposed. But, at the same time, the pressure of a non-volitional motive on the will may by itself be a sufficient ground for extenuation. In certain cases of mental disease a morbid impulse or idea may take such a despotic possession of the patient as to drive him to the infliction of an injury. He is mad, and yet he may be free from delusion and exhibit no marked derangement of intelligence. He may be possessed with an idea or impulse to kill somebody which he cannot resist. Or he may yield to a morbid impulse to steal or to set fire to houses or other property, without having any ill-feeling against the owner or any purpose to serve by what he does.[112] The deed to which the patient is driven is frequently one which he abhors, as when a mother kills the child which she loves most.[113] In such cases the agent is of course acquitted by the moral judge, and if he is condemned by the law of his country and its guardians, the reason for this can be nothing but ignorance. We must remember that this form of madness was hardly known even to medical {299} men till the end of the 18th century,[114] when Pinel, to his own surprise, discovered that there were "many madmen who at no period gave evidence of any lesion of the understanding, but who were under the dominion of instinctive and abstract fury, as if the affective faculties had alone sustained injury."[115] And there can be no doubt that the fourteen English judges who formulated the law on the criminal responsibility of the insane, made no reference to this _manie sans délire_ simply because they had not sufficient knowledge