“Your noble son is mad: Mad call I it; for, to define true madness, What is‘t but to be nothing else but mad?” To the legal mind, the chief character of insanity is the presence of _delusion_; but this view is far too restricted. It was first advanced by Erskine in the trial of Hadfield. Before that trial the doctrine was that every man was responsible for his acts, unless he was totally deprived of his understanding and memory, and did not know what he was doing, “no more than an infant, than a brute, or a wild beast” (R. _v._ Arnold). In the case of Bellingham, the knowledge of “right” and “wrong” in the abstract was the test of mental unsoundness; and, as in the opinion of the judge and jury he was held to be capable of solving this metaphysical problem, Bellingham was duly hanged. Since the trial and acquittal of MacNaughton on the ground of insanity, the doctrine of the knowledge of abstract right and wrong has been changed to a knowledge of right and wrong in relation to the particular act of which the person is accused, and also at the time of committing it. It has also been held that, on the assumption that a person labours under partial delusion only, and is not in other respects insane, he must be considered in the same situation as to responsibility as if the facts, with respect to which the delusion exists, were real. For example, if, under the influence of delusion, he supposes another man to be in the act of attempting to take his life, and he kills that man, as he supposes, in self-defence, he would be exempt from punishment. If his delusion were that the deceased had inflicted a serious injury on his character and fortune, and he killed him in revenge for such supposed injury, he would be liable to punishment. “Here,” says Maudsley, “is an unhesitating assumption that a man, having an insane delusion, has the power to think and act in regard to it _reasonably_, ... that he is, in fact, bound to be reasonable in his unreason, sane in his insanity.” Yet this was the doctrine laid down by the judges in answer to certain questions propounded by the House of Lords after the acquittal of MacNaughton (see Maudsley‘s _Responsibility in Mental Disease_, pp. 88 _et seq._). As laid down by English lawyers, madness absolves from all guilt in criminal cases. Where the deprivation of the understanding and memory is total, fixed, and permanent, it excuses all acts; so, likewise, a man labouring under adventitious insanity is, during the frenzy, entitled to the same indulgence, in the same degree, as one whose disorder is fixed and permanent (Beverley‘s Case, Co. 125, Co. Litt. 247, 1 Hale 31). “But the difficulty in these cases is to distinguish between a total aberration of intellect and a partial or temporary delusion merely, notwithstanding which the patient may be capable of discerning right from wrong; in which case he will be guilty in the eye of the law, and amenable to punishment.”[17]