The defence of irresistible impulse has been the subject of legislation in some states, as in New York and Michigan, where by statute a morbid propensity, or uncontrol lable impulse to commit a crime, in the mind of one who is conscious of the nature of the act or that it is wrong, or to be incapable of such knowledge, is no defence. See N. Y. Pen. Code § 21; Mich. Pen. Code §§ 19, 20.
What is sometimes called moral insanity, as distinguished from mental unsoundness, is not a defence to a charge of crime; Whart. & St. Med. Jur. §§ 164, 174; Tayl. Med. Jur. 677 ; 6 Jur. 201; 4 Cox, C. C. 149 ; Coin. v. Heath, 11 Gray (Mass.) 303; Flanagan v. People, 52 N. Y. 467, 11 Am. Rep. 731; Peo ple v. McDonell, 47 Cal. 134; People v. Ker rigan, 73 Cal. 222, 14 Pac. 849 ; Guiteau's Case, 10 Fed. 161; State v. Potts, 100 N. C. 457, 6 S. E. 657; People v. Wood, 126 N. Y. 269, 27 N. E. 362; Flanagan v. People, 52 N. Y. 469, 11 Am. Rep. 731; but see Smith v. Cora., 1 Duv. (Ky.) 224; Scott v. Cora., 4 Mete. (Ky.) 227, 83 Am. Dec. 461; Ander sen v. State, 43 Conn. 514, 21 Am. Rep. 669; St. Louis Mut. Life Ins. Co. v. Graves, 6 Bush (Ky.) 268. See also Mann, Med. Jur. of Insan. 66, 120, 135. Nor, however violent and unnatural, will it defeat a will unless it is the emanation of a delusion; Taylor v. McClintock, 87 Ark. 243, 112 S. W. 405.
Morbid religious feelings may be of such a character as to amount to partial insanity, which, though sometimes the basis of de lusions affecting criminal cases, is more fre quently met with in connection with the subject of undue influence. In a case in which it was alleged that a testator was insane on the subject of spiritualism, it was held that, as an abstract proposition, a be lief in spiritualism, though a person may be a monomaniac on that subject or any other form of religion, does not prove in sanity; Connor v. Stanley, 72 Cal. 556, 14 Pac. 306, 1 Am. St. Rep. 84; Chafin Will Case, 32 Wis. 557; Will of Smith, 52 Wis. 543, 8 N. W. 616, 9 N. W. 665, 38 Am. Rep. 756 ; Turner v. Hand, 3 Wall. Jr. 88, Fed. Cas. No. 14,257 ; nor belief in the trans migration of souls; Bonard's Will, 16 Abb. Pr. N. S. (N. Y.) 128.
Insanity is not necessarily established by mere eccentricity of mind, manifesting it self in absurd opinions or extravagancies of dress and manners; Lee's Heirs v. Lee's Ex'rs, 4 McCord (S. C.) 183, 17 Am. Dec. 722 ; or an irritable temper and an excitable disposition ; Willis v. People, 32 N. Y. 715; or depression coupled with a monomania or delusion that, by the lands wearing out and buildings going to ruin, starvation and the poorhouse were threatened ; Gillespie v.
Shuliherrier, 50 N. C. 157. Insanity pro duced by continued dissipation is a good de fence; State v. Harrigan, 9 Houst. (Del.) 369, 31 Atl. 1052 ; mania d potu is a species of insanity ; State v. Dillahunt, 3 Harr. (Del.) 551; and so is delirium, tremens; People v. O'Connell, 62 How. Pr. (N. Y.) 436; Maconnehey v. State, 5 Ohio St. 77; Kelley v. State, 31 Tex. Cr. R. 216, 20 S. W. 357; but it must be shown to exist at the time the act is perpetrated; not antecedently; State v. Sewell, 48 N. C. 245. As to enness in its varied forms, see that title.
If the accused was wanting in self-govern ing power, whether caused by insanity, gross intoxication Or other controlling influences other than depravity or wickedness of heart, then his mind was not fully conscious of its own purposes and he was not guilty of mur der in the first degree ; Com. v. Van Horn, 188 Pa. 143, 41 Atl. 469. Where a defendant was insane from drugs, the court must charge thereon, though a charge on the gen eral issue of insanity is given ; Burton v. State, 46 Tex. Cr. R. 493, 81 S. W. 742. If the accused had sufficient mind to know right from wrong and to understand the na ture and quality of the act, he was sane in law ; Eckert v. State, 114 Wis. 160, 89 N. W. 826 ; if he did not possess the power to avoid the wrong and do the right, he was irrespon sible ; People v. Barthleman, 120 Cal. 7, 52 Pac. 112 ; Abbott v. Com., 107 Ky. 624, 55 S. W. 196 ; Jolly v. Com., 110 Ky. 190, 61 S. W. 49, 22 Ky. Law Rep. 1622.
Suicide is not conclusive evidence of insan ity, but is admissible to show the absence of a sound and disposing mind ; Pettitt's Ex'rs v. Pettitt, 4 Humph. (Tenn.) 191. Epilepsy alone does not establish insanity which will excuse crime ; Lovegrove v. State, 31 Tex. Cr. R. 491, 21. S. W. 191; Com. v. Buccieri, 153 Pa. 535, 26 Atl. 228 ; and in its milder forms, causing temporary fits of insanity, the prima facie presumption is in favor of men tal soundness ; Corbit v. Smith, 7 Ia. 60, 71 Am. Dec. 431. See 3 Witth. & Beck. Med. Jur. 319. Proof that insanity was heredita ry is admissible ; Shaeffer v. State, 61 Ark. 241, 32 S. W. 679; but that alone is insuffi cient when the other evidence clearly shows that defendant knew that he was committing a wrong ; Lovegrove v. State, 31 Tex. Cr. R. 491, 21 S. W. 191; Snow v. Benton, 28 Ill. 306.