§ 9.02 Voluntary Act: General Principles
[A] General Rule
Subject to a few limited and controversial exceptions,15 a person is not guilty of a crime unless her conduct includes a voluntary act. Few statutes defining criminal offenses expressly provide for this requirement. Nonetheless, the voluntary act requirement has common law support, modern courts usually treat it as an essential, albeit implicit, element of criminal statutes,16 and an increasing number of states now include a general statutory provision, cast in terms similar to the Model Penal Code, that sets out this requirement.17
For analytical purposes, the voluntary act rule may be separated into two components, the "act" and its "voluntary" nature.
[B] The "Act"
For purposes of the actus reus requirement, an "act" is, simply, a bodily movement, a muscular contraction.18 A person "acts" when she pulls the trigger of a gun, raises her arm, blinks her eyes, turns the ignition key in an automobile, or simply puts one leg in the front of the other to walk. Understood this way, an act involves physical, although not necessarily visible, behavior. For example, the muscular contractions involved in talking—the movements of the vocal chords and tongue—constitute "acts" for present purposes. However, the term "act" excludes the internal mental processes of thinking about, or of developing an intention to do, a physical act (e.g., "mental acts").
Three aspects of the term "act" should be noted here. First, sometimes there can be bodily movement, but really no "act" at all by the person whose body has moved. For example, if A grabs B's arm and swings it into C's body, B has not acted (voluntarily or involuntarily), although her arm has moved. In this case, B's arm was simply propelled, like a leaf blown by the wind, as the result of A's act of grabbing her arm.
Second, the term "act" does not apply to the results of a person's bodily movements. For example, suppose that D, intending to kill V, places dynamite around V's house, where V is asleep, and then activates a detonator that causes an explosion, killing V. In a criminal homicide prosecution, the pertinent acts by D are the positioning of the dynamite around V's house and her activation of the detonator. The term "act," however, does not include the result of D's acts, i.e., V's death. The latter constitutes the "social harm" element of the actus reus.19
Third, some courts and scholars contend that, to be an "act"—or, more specifically, a human act—the muscular contraction must itself be voluntarily performed (as defined below). As one court put it, "[a]n [involuntary] 'act' . . .is in reality no act at all. It is merely a physical event . . . ."20 Most modern lawyers and the Model Penal Code,21 however, use the term "act" as it is defined in this subsection, as any bodily movement that is voluntarily or involuntarily performed, as these terms are discussed immediately below.
[C] "Voluntary"
Unfortunately, the word "voluntary" is used by criminal lawyers in two different senses. The two usages of the term are often confused. It is important to be able to distinguish between these two usages.
[1] Broad Meaning: In the Context of Defenses
The terms "voluntary" and "involuntary" are often used by lawyers and courts in discussing criminal law defenses to express the general conclusion that the defendant possessed or lacked sufficient free choice to be blamed for her conduct.22 Thus, it is sometimes said that a person who acted under duress (e.g., commits a crime because a loaded gun is pointed at her child's head) or as the result of a mental disorder acted "involuntarily." This simply means that because the actor faced an extremely hard choice (duress) or was irrational (insane), she does not deserve to be punished for her actions. However, this is not how the term "involuntary" is used in the context of the actus reus requirement, the topic of this chapter.
[2] Narrow Meaning: In the Context of the Actus Reus
The term "voluntary" has a narrow meaning when used to determine whether the actus reus of an offense has occurred. Nineteenth-century scholar John Austin defined a "voluntary act" in this sense as a "movement of the body which follows our volition."23 Similarly, Holmes described it as a "willed" contraction of a muscle.24
What did Austin mean by "volition," or Holmes by a "willed" act? Austin posited a view of human behavior, in which a person consciously decides to move a part of the body, and then that part of the body "invariably and immediately [follows] our wishes or desires for those same movements."25 Applying this definition, nearly all human acts are voluntary,26 and thus it may be more useful to give examples of involuntary acts. Examples of these "include reflexive actions, spasms, seizures or convulsions, and bodily movements while the actor is unconscious or asleep."27
Austin's explanation of volition is too simplistic. Today, we realize that bodily movements occur as the result of complicated physiological and psychological mechanisms, many of which are not fully understood even now. However, no human act occurs simply as the result of wishing it to take place.28 A person receives stimuli from outside and from within herself, which themselves act as further stimuli, some of which ultimately produce electrical impulses from the brain that result in bodily movements.29
So, what does it really mean to say that a person may not be punished unless her conduct includes a voluntary—"willed"—act? The concept of volition is tied to the notion that criminal law responsibility should only attach to those who are accountable for their actions in a very personal way. As Professor Sanford Kadish once explained it, the criminal law distinguishes
between genuine human actions, which are susceptible of praise and blame, and mere events brought about by physical causes which happen to involve a human body. . . . When a person claims the involuntary-act defense he is conceding that his own body made the motion but denies responsibility for it.30
Professor Kadish's point can be seen if one considers the difference in meaning of the following two sentences: (1) "I raised my arm"; and (2) "My arm came up."31 Both statements suggest that bodily movement has occurred. Yet, the difference in language expresses our understanding of the difference between a voluntary act (sentence (1)) and an involuntary one (sentence (2)). In both cases, the arm movement was the result of impulses from the actor's brain. But, in the first sentence, the implication is that the act was the result of something more than mere physiological brain activity. That extra "something" was the more sophisticated thought process that goes into the decision—the choice—to raise one's arm. Put slightly differently, a voluntary act involves the use of the human mind; an involuntary act involves the use of the human brain, without the aid of the mind.32 With a voluntary act, a human being—a person—and not simply an organ of a human being, causes the bodily action.
Thus, when D's arm strikes V as the result of an epileptic seizure, we sense that D's body, but not D the person, has caused the impact. In the context of the criminal law, the movement of D's arm is conceptually the same as a tree branch bending in the wind and striking V. When D "wills" her arm to move, however, we feel that d, and not simply her arm, is responsible for V's injury. Her "acting self" is implicated. A personal, human agency is involved in causing the bodily contact.33 Another way of making this point is to say, as H.L.A. Hart has put it, that involuntary acts are "inappropriate" actions, i.e., they are bodily movements not "required for any action . . . which the agent believed himself to be doing." They are "wild" acts, "not 'governed by the will' in the sense that they are not subordinated to the agent's conscious plans of action."34
Before we move on, three clarifications should be noted, to avoid future confusion. First, one should be careful not to assume that an act is, legally speaking, involuntary simply because the actor is unaware of what she is doing while she is doing it. For example, people act habitually: A chain-smoker may light up a cigarette "without thinking"; and a driver coming home from work may change lanes on the freeway at precisely the same place each day without even noticing that she is doing this. Although, at our best, we are aware of both our external and internal (mental) surroundings, sometimes we "don't notice that [we] notice . . . . [We are] aware of everything except [ourselves]."35 In this sense, consciousness is a matter of degree,36 and the law treats habitual acts as falling on the voluntary side of the continuum.
Second, it is important to distinguish between the "voluntary act" component of the actus reus of a crime and the mens rea component of a crime, discussed in the next chapter. The "mens rea" of a crime is the actor's culpable mental state regarding the result of her conduct, such as when a person, who fires a gun at the victim, intends the victim's death. The intent to cause the death of the victim is the mens rea of the crime in this example. The "voluntariness" requirement, however, relates to the willed act—pulling the trigger of the gun. This distinction can be crucial because a few offenses do not require any mens rea (they are so-called "strict liability offenses"), but this does not mean that the person may be convicted in the absence of a voluntary act.37
Third, a claim that an act was "involuntary" needs to be distinguished from an insanity claim by the defendant. For example, a defendant might claim that her act was involuntary as the result of a brain aneurysm; it can be confused with a claim of insanity, an entirely separate claim.38 This important distinction is developed further in subsection [E], infra.
[3] "Voluntariness": At the Controversial Edges
[a] Hypnotism
Suppose that X hypnotizes D to...
To continue reading
Request your trial