Impulse is a sudden and irresistible desire or force in a person that compels him to the conscious performance of some act for which there is no motive; for example, kleptomania means an irresistible desire to steal articles which may be of small value and even, may be of no use to the person stealing the article. A sane person who has self–control and judgment capacity may not finally give shape to his impulsive or compulsive desire. But an insane person, who lacks in self–control and judgment capacity, cannot resist the impulse and may commit any offence. Thus, in connection with commission of an unlawful act, impulse is a good defense for an insane person which is not so for a sane person. Some types of impulses are:
- Dipsomania: This is found in alcoholics who have an irresistible desire to take alcoholic drinks.
- Pyromania: Here, there is an irresistible desire to set fire to things, which may be important and valuable. The person is not conscious or careful, at least temporarily, to the possible dangers of his act.
- Mutilomania: This is an irresistible desire to injure and mutilate animals, commonly the domestic pets.
- Sexual impulse: The person may feel compulsive urge to perform sexual intercourse, often in a perverted way. There may be some psychic problem concerning the sexual behavior; or the person may be a victim of mental sub normality.