Used chief-ly ln criminal law, this term means an im-pulse to commit an unlawful or crimlnal act which cannot be resisted or overcome by the patient because Insanity or mental disease has destroyed the freedom of hls will and hls power of self-control and of choice as to his actions. See McCarty v. Com., 114 Ky. 620, 71 S. W. 058; State v. Knight, 95 Me. 467, 60 Atl. 276, 55 L. R. A. 373; Leache v. State, 22 Tex. App. 279, 3 S. W. 539, 58 Am. Rep. 638; State v. Peel, 23 Mont. 358, 59 Pac. 169, 75 Am. St. Rep. 529. And see IN-sANITY