Actus Reus - Voluntariness

Voluntariness

For conduct to constitute an actus reus, it must be engaged in voluntarily. Few sources enumerate the entirety of what constitutes voluntary and involuntary conduct. Oliver Wendell Holmes, in his 1881 book The Common Law, disputed whether such a thing as an involuntary act exists: " spasm is not an act. The contraction of the muscles must be willed." A few sources, such as the Model Penal Code, provide a more thorough treatment of involuntary conduct:

1. a reflex or convulsion;
2. a bodily movement during unconsciousness or sleep;
3. conduct during hypnosis or resulting from hypnotic suggestion;
4. a bodily movement that otherwise is not a product of the effort or the determination of the actor, either conscious or habitual.