Elements of the Test

Elements of the Test

The history just traced explains why § 4.01(1) joins two capacities and loosens both, and the sentence it produced can now be turned into an order of operations. Its conditions are cumulative in one respect and alternative in another. The disease condition, the causal and timing condition, and the substantiality condition must all be met in every case, but the capacity condition offers two routes, and only one of them has to be open.¹ Keeping that mixture straight matters on an exam, because the usual error is to treat the two routes as though both had to be shown.

The first three steps apply no matter which capacity is in play, so step four is the only place where the formula branches. The statute joins the two capacities with either and or, which makes them alternatives, and the Code's commentary confirms that the standard relieves a defendant of responsibility in two separate circumstances, one cognitive and one volitional.³ Proof of one lack therefore ends the capacity inquiry in the defendant's favor, and the other capacity can be fully intact.

Each part of this structure has its own reason. The capacities are alternatives because responsibility depends on both understanding and control, and impairment of either puts a person beyond the reach of deterrence. Someone who cannot grasp that an act is wrong cannot be warned off it, and someone who grasps the prohibition but cannot act on it cannot be held back by it. A cumulative rule would excuse only the defendants impaired in both ways and would leave out half of the group the law cannot deter. The disease condition at step one does different work. It ties the defense to a recognized disorder, so that a defendant's temper, poor judgment, or bad character cannot open the capacity inquiry by itself, however much any of them contributed to the offense.

The first defendant shows why knowledge that the act was wrong cannot be treated as the end of the analysis: it closes only the cognitive route, and the volitional route remains available. The second shows the opposite limit. A diagnosis answers step one and nothing more, so a defendant whose capacities are both substantially intact is held responsible whatever the label on the disorder.

The subsections that follow take the conditions in the order the sentence states them: the threshold of mental disease or defect, then the causal link and timing, then substantial capacity, and finally the cognitive and volitional prongs one at a time.

Mental Disease or Defect

The first condition in the formula is that the defendant suffered from a mental disease or defect, and the Code handles it in an unusual way: it gives no general definition and states instead one thing the phrase does not include. Section 4.01(2) provides that the terms "mental disease or defect" do not include "an abnormality manifested only by repeated criminal or otherwise anti-social conduct."⁵ Everything else about the disease element is left open. The omission has a defensible rationale, because a precise definition of the disorder is probably unattainable, and an open term is tolerable when the capacity conditions that follow supply the minimum a person must show before escaping accountability.⁶ Leaving the term open also matches how law generally treats medical vocabulary. In Kansas v. Hendricks, a civil commitment case, the Supreme Court observed that legislatures have traditionally defined medical terms that carry legal significance and that legal definitions of insanity and competency need not mirror the psychiatric ones.⁷ A clinician's diagnosis therefore informs the first step without settling it.

Courts decide what qualifies on the evidence before them. In Blake v. United States the Fifth Circuit observed that the defendant might have been a schizophrenic or might merely have had a sociopathic personality, that the evidence could go either way, and that the substantial-capacity standard left the existence of a mental defect, and its relationship to the conduct, for the jury to decide on lay and expert evidence.⁸ The Fifth Circuit's en banc decision in United States v. Lyons draws a comparable line for another condition. It recognized that actual physical damage to the brain falls within the phrase, while evidence of narcotics addiction standing alone, without other physiological or psychological involvement, raises no issue of mental disease or defect.⁹

The exclusion in § 4.01(2) has a specific target. The drafters designed it to remove the so-called psychopathic personality from the concept of mental disease or defect, and they gave two reasons for doing so.¹⁰ The first concerns classification: the psychopath differs from a normal person only in degree, and there is considerable disagreement about whether psychopathy should be called a disease at all.¹¹ The second reason is circularity, and it does subtler work. The defense requires that the lost capacity result from a disease, yet the only evidence that a psychopathic disorder exists is the behavior itself, repeated crime. If that behavior could establish the disease, the same conduct would be both what needs excusing and the sole proof of the disorder meant to excuse it, and a criminal record, which ordinarily weighs against a defendant, would become the diagnosis. The drafters accordingly excluded a condition manifested only by the behavior that must, by hypothesis, be the result of disease, and in doing so avoided trials over what is essentially a matter of terminology.¹²

In operation, the exclusion filters the evidence offered to prove the disease and leaves untouched the question whether the defendant has some other disorder.

The second defendant fails at step one, and the third shows why the exclusion is narrower than a rule against defendants with criminal histories. Students lose this issue when they treat a criminal record as disqualifying in itself, or when they treat a label such as antisocial personality as proof of a disease. The inquiry turns on whether a separate recognized disorder exists apart from the conduct. Clearing step one shows only that the capacity inquiry may begin, and the third defendant must still prove that the schizophrenia caused a substantial lack of capacity at the time of the offense, which the following subsections address.

The Code's treatment of the disease element is not uniform across the jurisdictions that follow it. Some courts that adopted the basics of the Code test rejected paragraph (2), as the Sixth Circuit did in United States v. Smith.¹³ Doubts about the exclusion's soundness and effectiveness led some courts to adopt modified forms of the test with no express exclusions, although most legislative enactments retain it.¹⁴ Other courts supplied a definition of their own. In United States v. Brawner the D.C. Circuit overruled Durham and placed the McDonald definition on top of the Code test, so that the disease became an abnormal condition of the mind that substantially affects mental or emotional processes and substantially impairs behavior controls.¹⁵ Statutes sometimes change the vocabulary without changing the exclusion. The instruction the prosecution proposed in State v. Uyesugi, a Hawaii case, speaks of a "physical or mental disease, disorder or defect" yet repeats in plain language that the term does not include an abnormality manifested only by repeated criminal or otherwise antisocial conduct.¹⁶ Beyond the Code states, Clark v. Arizona noted that jurisdictions limit in varying degrees which mental illnesses can support an insanity defense. It contrasted Arizona's exclusion of acute voluntary intoxication, withdrawal, character defects, psychosexual disorders, and impulse control disorders with Indiana's exclusion of an abnormality manifested only by repeated unlawful or antisocial conduct, which tracks the Code.¹⁷

On an exam, the safe approach is to apply paragraph (2) as written unless the question identifies a jurisdiction with its own definition, and then to ask whether the stated abnormality is shown by anything other than the defendant's offending.

Causal Link and Timing

Two short phrases in § 4.01(1) connect the disease element to the capacity element and fix the moment at which the whole inquiry is conducted. The impairment of capacity must occur “as a result of” the mental disease or defect, and it must exist “at the time of such conduct.”¹⁹ Because both phrases sit in the middle of a long sentence, they are easy to skim past, yet each settles a different question on exam facts. The first decides which of the defendant's problems count toward the defense, and the second decides when the defendant's mind is examined.

The grammar of the sentence shows what must flow from the disease. What occurs “as a result of” the disorder is the defendant's lack of substantial capacity, so the causal link connects the disease to the incapacity.²⁰ This is where the Code departs from Durham. The Durham rule asked whether the crime was the product of the disease, while the Code asks what impact the disease had on the defendant's cognitive or behavioral capacities.²¹ The drafters gave up the Durham formulation because of the ambiguity of the word “product.”²² A test that asks whether an act was the product of a disease gives the fact-finder no measure of how much connection is enough. The experience under Durham showed the cost: with no standard by which to measure the accused's competency, the fact-finder was left to follow the labels psychiatrists attached to the defendant, and the experts in effect took over the jury's function.²³

Framing the inquiry around capacity gives experts and jurors a question they can actually answer. A clinician can describe how a disorder affects a person's understanding and self-control, and jurors can then judge whether the effect was serious enough, without anyone having to trace an unobservable chain from diagnosis to offense. The court that adopted the Code test in United States v. Freeman made this point when it explained that the formulation relieves judge and jury of the burden of divining precise causal relationships, leaving them free to concentrate on the ultimate decisions that belong to them.²⁴ The causal phrase also keeps the defense from reaching defendants whose disorder is merely incidental to the offense. A diagnosis in the file does nothing for a defendant whose capacities were substantially intact when he acted, because then there is no lost capacity to attribute to the disease.

In the first pair the delusion accounts for the lost capacity, and in the second the diagnosis accounts for nothing. Students lose this issue when they ask whether the disease caused the crime, because that is the Durham question the Code set aside. The Code asks what the disease did to the defendant's capacities at the moment of acting, and a defendant who committed an offense for ordinary reasons while fully capable cannot satisfy that inquiry however serious the diagnosis.

Critics have argued that the word “result” brings back the Durham “product” ambiguity.²⁵ The objection has force only if the word is read to link the disease to the crime. Read where the Code places it, the word links the disease to the incapacity, and the content of that incapacity is given definite shape by the two named capacities and the requirement of substantiality, which the following subsections take up. Defenders of the formulation add that the Durham experience showed a precise definition to be impossible, and that the Code's formula expresses an intelligible principle and discloses that principle to the jury.²⁶ The sentence attaches no named causation standard to the phrase, so an answer should apply the words as written and ask whether the lost capacity is traceable to the disorder.²⁷

The second phrase fixes the moment of measurement. The test exists to exclude from penal sanctions people who cannot be deterred, and the drafters kept the cognitive and volitional questions because both conditions bear on that goal.²⁸ Whether a prohibition could operate on a person depends on what that person could understand and control when choosing to act, and the capacities of someone with a disorder can change as symptoms come and go. A diagnosis from last year, or a breakdown that follows arrest, therefore says nothing by itself about the capacity that matters. Evidence from before and after the offense can help the fact-finder infer the defendant's condition at the moment, but the element is the condition at the moment.

The later breakdown in the first pair goes to a different question, whether the defendant is competent to stand trial, which is tested by a different definition from the one used for the defense.²⁹ The Code treats that question separately, under the fitness-to-proceed provision discussed later in this chapter.

A jury instruction shows how the two phrases reach the fact-finder. In State v. Uyesugi, a Hawaii case, the instruction originally proposed by the prosecution followed the Code's structure and told the jury to return a verdict of not guilty by reason of mental disease, disorder, or defect upon two findings. The first was that at the time of the charged offense the defendant was suffering from the disease, disorder, or defect. The second was that as a result of it he lacked substantial capacity either to appreciate the wrongfulness of his conduct or to conform it to the requirements of law.³⁰ The two findings do separate work. The first fixes the disorder at the moment of the offense, which is the timing condition applied to the disease itself, and the second asks what the disorder did, which is the causal condition applied to capacity. A jury can accept the first and reject the second, as when it credits a diagnosis but finds the defendant's understanding and self-control substantially intact. The instruction's preponderance language concerns the burden of proof, which a later section takes up.

Substantial Capacity

Once the disease is established and the incapacity is traced to it at the time of the conduct, § 4.01(1) asks how much capacity the defendant must have lost. The answer sits in one adjective that precedes both alternative capacities: the defendant must lack substantial capacity either to appreciate the wrongfulness of the conduct or to conform it to the requirements of law.³² The drafters regarded the adoption of that standard as perhaps the most significant change the Code made to the tests it replaced.³³ The next two subsections take up the two capacities separately. This one fixes what the quantity word means, why the drafters preferred it to a rule of total incapacity, and how a jurisdiction's own jury wording can differ from the Code's.

The word substantial modifies capacity. It does not modify the disorder, and the Code attaches no severity label to the disease itself. A defendant lacks substantial capacity when the ability that remains falls short of “a capacity of some appreciable magnitude when measured by the standard of humanity in general,” so that what is left has shrunk to the “vagrant and trivial dimensions” characteristic of the most severe afflictions of the mind.³⁴ Two features of that measure matter on exam facts. The yardstick is the capacity of people generally, which gives jurors a familiar benchmark in place of a clinical scale. The word also cuts in both directions: it makes clear that any incapacity is not enough to avoid responsibility, yet total incapacity is unnecessary.³⁵

The drafters had reasons for refusing to demand a total loss, and the reasons come from how mental disorder presents and how it is proved. Clinical experience showed a graded scale with marks along the way rather than an on-off switch, so disorientation might be extreme and still fall short of total.³⁶ Proof raises a second problem, because the lost capacity must be established for a moment that the witnesses did not observe. The drafters noted that a lack of substantial capacity is all that candid witnesses, asked to infer a situation they did not see, can confidently say, even when they know the disorder was extreme.³⁷ A rule requiring total absence would therefore ask experts to assert something they could rarely assert, and a defendant could lose only because no witness was willing to swear to an absolute.

A second reason concerns whom the defense is meant to reach. The Code keeps the cognitive and volitional questions in order to exclude from penal sanctions the people who cannot be deterred, and the drafters recognized many cases of advanced disorder in which rudimentary capacities of cognition and volition survive but criminal punishment is still plainly inappropriate.³⁸ A threshold of total incapacity would return those defendants to conviction on the strength of a remnant of capacity that could not realistically have operated as a restraint. Measured against the older and newer tests, the standard sits between two extremes: M'Naghten and irresistible impulse were generally thought to require a total lack of capacity, while Durham could be read to require only a slight impairment.³⁹ Earlier decisions had also sometimes suggested that complete or total destruction of mental capacity was required, and the single word substantial removes that implication.⁴⁰

The drafters did not define the word with greater precision, and they said so openly. They acknowledged that “substantial” imputes no specific measure of degree but concluded that identifying the degree of impairment with precision was “impossible both verbally and logically.”⁴¹ The word is open-ended, yet its quantitative connotation was thought precise enough for practical administration, because the law is full of instances in which courts and juries are authorized to confront an issue of degree, as with recklessness and negligence.⁴² The consequence is that substantiality is decided by the jury on lay and expert evidence, and a jurisdiction that wants more guidance has to supply its own wording.

The practical difference between a total-incapacity rule and a substantial-capacity rule appears in Blake v. United States, where the Fifth Circuit adopted the Code's definition of insanity.⁴³ Blake's adult life had been a long round of psychiatric confinement and drinking when not confined, and at his trial for bank robbery the evidence indicated a severe mental disease that the jury might have found impaired his control over the conduct.⁴⁴ The record did not show complete disorientation, since he was not unconscious, was not incapable of distinguishing right from wrong, and had not lost his will entirely. He could not have prevailed under a charge demanding total incapacity, but he might have prevailed under a charge asking about a substantial lack of capacity, so the court reversed the conviction and left the question to the jury.⁴⁵

Because the diagnosis and timing were held constant, the only variable in that pair is how much capacity remained. The standard measures what is left rather than how serious the label on the disorder sounds, so a grave diagnosis does not settle the element by itself. A delusional defendant who retains some idea of what he is doing, or of whether it is wrong, fails under M'Naghten yet may still lack substantial capacity under the Code.⁴⁶ Even so, few mentally ill defendants qualify under the Code's more flexible test.⁴⁷

Jurisdictions that use the Code's language sometimes put their own gloss on it when they instruct juries, and the gloss should not be mistaken for the Code's text. In State v. Uyesugi, a Hawaii case, the instruction the prosecution proposed said that a person lacks substantial capacity if his capacity has been “extremely limited” by the disease, disorder, or defect. It added that the phrase does not mean a total lack of capacity but capacity impaired to such a degree that only an extremely limited amount remains.⁴⁸ That instruction agrees with the Code on the point that matters most, which is that total incapacity is not required. Its wording about how little capacity may remain is the jurisdiction's own formulation, whereas the drafters' measure speaks of capacity of appreciable magnitude by the standard of humanity in general and does not use the instruction's phrasing.⁴⁹ On an exam, a jurisdiction's own gloss governs only where the question supplies it. Otherwise the answer applies the Code's text and the drafters' measure and states that the defendant need not have lost all capacity.

The Cognitive Prong

With the quantity of lost capacity settled in the preceding subsection, the next question is what the defendant must have lost the capacity to do. Section 4.01(1) names two alternatives, and the first is the cognitive prong: because of mental disease or defect, the defendant lacks substantial capacity to appreciate the criminality [wrongfulness] of the conduct.⁵¹ Either alternative suffices, so the volitional prong taken up in the next subsection is a separate route to the same defense. Three features of the wording decide how this prong works: the verb “appreciate,” the bracketed choice between “criminality” and “wrongfulness,” and, once a legislature selects “wrongfulness,” the question whose morality supplies the standard. The prong is a variant of the moral-incapacity strain that the second alternative in M’Naghten supplies, an inability to understand that one’s act is wrong, and when the Supreme Court surveyed American insanity standards in Clark v. Arizona it counted fourteen Code-inspired jurisdictions that pair some variant of that strain with a volitional test, with either one enough to excuse.⁵²

The drafters’ choice of “appreciate” over “know” is the first departure from M’Naghten’s wording. “Know” can naturally be read to mean simple awareness, of the kind a defendant displays by acknowledging in words that the conduct is forbidden, whereas “appreciate” conveys a broader sense of understanding than simple cognition.⁵³ The reason is a gap the drafters found in a knowledge test. Such a test permits a finding of responsibility for a defendant who is not seriously deluded about the conduct or its consequences, yet whose awareness of its wrongfulness is detached and abstract and never penetrates to the emotional level, and it applies awkwardly to disorders of emotion.⁵⁴ Under that test, a defendant can be held responsible on the strength of a recital the disease has emptied of meaning. The Code closes the gap by asking whether the defendant could grasp the wrongfulness in a fuller sense, so a bare verbal acknowledgment does not end the inquiry.

Because “appreciate” reaches the emotional side of understanding, the affective features of the defendant’s personality become relevant, and expert testimony about them bears directly on this prong.⁵⁵ Proponents also noted that the change expresses the broader reading of M’Naghten, under which a sane offender must be emotionally as well as intellectually aware of the significance of the conduct.⁵⁶ In United States v. Freeman, a federal court of appeals adopting § 4.01 for its circuit made a similar observation: intellectual awareness that conduct is wrongful, divorced from understanding of its moral or legal import, has little significance.⁵⁷ The function of the cognitive inquiry explains the choice. The Code keeps the cognitive and volitional questions in order to exclude from penal sanctions the people who cannot be deterred, and a prohibition that registers with someone only as a memorized phrase gives that person no meaningful restraint.⁵⁸

The brackets in “criminality [wrongfulness]” record a choice the drafters left open.⁵⁹ The proposal approved in 1955 spoke of capacity to appreciate “criminality,” and the Institute later accepted “wrongfulness” as an appropriate substitute in the Proposed Final Draft.⁶⁰ By printing the two words together, the drafters purposefully left each state legislature to decide which of them describes the conduct a defendant must be unable to appreciate, and “wrongfulness” was offered so that any legislature that wished could introduce a moral question into the test.⁶¹ The two words point the inquiry at different subjects. Appreciating wrongfulness has been understood to mean appreciating that the community regards the behavior as wrongful, which is a moral judgment, while “criminality” lacks that moral element and points to the legal prohibition.⁶² Reasonable legislatures disagree about whether the cognitive inquiry should concern legal prohibition or moral condemnation, and the bracket lets each answer for itself. Courts applying M’Naghten faced a similar choice in reading “wrong,” and a majority of those jurisdictions read the word to cover legal as well as moral wrong.⁶³ On an exam, the statute in the problem fixes which word governs, and the moral inquiry that follows arises only when the word is “wrongfulness.”

Once a legislature has chosen “wrongfulness,” the harder question is whose moral standard the word invokes. A defendant can argue for a personal measure, under which a disease-driven belief that the act was morally justified is enough even when the defendant knows the act is illegal and condemned by the community. The state can argue for a societal measure, under which the defendant is responsible unless the disease left him without substantial capacity to appreciate that the act was wrong by society’s standards. One state court, reading a statute modeled on § 4.01, adopted the societal measure: a model jury charge associated with the Code’s drafting describes a person who may know the facts of the conduct and still be quite incapable of grasping that it is wrong in the sense of being condemned by the law and commonly accepted moral standards, and the court concluded that the drafters did not intend to excuse a defendant who appreciates both the illegality and the societal immorality of the act because of a purely personal, even delusional, moral code.⁶⁴

That court also observed that the large majority of other jurisdictions to consider the question had chosen a societal standard over a personal one.⁶⁵ A federal court of appeals applying the federal M’Naghten-style statute reached the same result in United States v. Ewing, defining wrongfulness by objective societal or public standards of moral wrongness rather than the defendant’s subjective personal standards.⁶⁶ The societal standard is therefore the leading approach. It remains one court’s reading of a Code-based statute and is not the Code’s own rule, because the Code leaves even the choice of the bracketed word to each legislature.⁶⁷

The same court did not stop at a bare societal standard, because asking only what society actually thinks would ignore what the disease does to a delusional defendant’s picture of the world. It held that a defendant may establish lack of substantial capacity to appreciate wrongfulness by proving that, at the time of the act and as a result of mental disease or defect, he substantially misperceived reality and harbored a delusional belief that society, under the circumstances as he honestly but mistakenly understood them, would not have morally condemned his actions.⁶⁸ The safeguard operates on the facts the defendant believes. A defendant who falsely believes a victim is about to kill him has not rejected the community’s moral standards. The delusion has changed the situation to which those standards apply, and in the situation he imagines he believes the community would approve of defending oneself. Because the disease falsified the circumstances the law’s command was addressed to, the person is beyond that command’s reach in the way the cognitive inquiry is meant to detect.⁶⁹

Students lose this prong when they treat a purely personal moral code as enough. A sincere belief that the act was justified does not satisfy the prong when the defendant knows the act is illegal and knows the community condemns it, because that defendant has received the message the law sends and rejected it on private grounds. The question to ask on exam facts is what the disease distorted. If it falsified the defendant’s perception of reality, and with it the defendant’s sense of how society would judge the act, the prong may be met. If the defendant saw reality and society’s verdict accurately and simply disagreed with it, the prong is not met.

Jurisdictions that use the Code’s language often leave these key words to ordinary meaning at trial. In State v. Uyesugi, the Hawaii case from the preceding subsection, the instruction the prosecution proposed defined what it means to lack substantial capacity but, as quoted, supplied no definition of “appreciate” or “wrongfulness,” and the defense instructions that were later withdrawn did not define them either.⁷⁰ The circuit court also instructed that words in the instructions carry their usual sense in context.⁷¹ Whether a jury in such a jurisdiction hears a societal-standard gloss therefore depends on that jurisdiction’s own law. An exam answer should apply the societal standard with the delusion safeguard as the leading reading of “wrongfulness,” and should defer to the problem if it supplies a different instruction or a statute that uses “criminality.”

The Volitional Prong

The second alternative in § 4.01(1) shifts the question from what the defendant could understand to what the defendant could control. Under the volitional prong, a person is not responsible if, because of mental disease or defect, the person lacks substantial capacity to conform conduct to the requirements of law.⁷³ Either alternative is enough, so a defendant who fully appreciated that the act was wrongful can still be excused here, and the substantiality standard from the earlier subsection governs this prong just as it governs the cognitive one. The idea behind the prong is older than the Code. The volitional-incapacity or irresistible-impulse test surfaced over two centuries ago and asks whether a person was so lacking in volition, because of a mental defect or illness, that the person could not have controlled the act, and in Clark v. Arizona the Supreme Court counted it among the four traditional strains that American jurisdictions combine in different ways.⁷⁴ The Code restates that idea instead of adopting it unchanged, and the restatement makes sense once the reason for keeping a volitional alternative is on the page.

The reason lies in a gap the drafters found in M’Naghten. A test built on knowledge misses the defendant whose disorder destroys or overrides the power of self-control, and the drafters called this the second and more pervasive difficulty with that standard.⁷⁵ The purpose of the Code’s two questions shows why the gap matters: impaired cognition and impaired volition are the two conditions that must be taken into account in an effort to exclude from penal sanctions those who cannot be deterred.⁷⁶ Punishment works by giving a person a reason to hold back, and that mechanism fails for someone whose disease has removed the ability to hold back, however clearly the person understands that the act is forbidden. Condemning such a person is as futile as condemning someone who does not know what is being done. The drafters gave exactly that reasoning for exculpating the M’Naghten category: those it covers are beyond the restraining influence of the law, so their condemnation would be futile and unjust.⁷⁷ Courts adopting the Code test have accordingly singled out its requirement that the jury consider volitional as well as cognitive impairments.⁷⁸ Outside the Code itself, a dissenting opinion in Kansas v. Hendricks, a civil-commitment case and not a § 4.01 case, likewise described § 4.01 as resting in part on inability to conform conduct to the law and observed that irresistible impulse has often helped shape the insanity defense.⁷⁹

The first improvement over irresistible impulse is quantitative. A rule demanding utter incapacity for self-control restricts the inquiry unrealistically, because clinical experience showed a graded scale with marks along the way rather than an all-or-nothing switch, and an examiner asked only about total loss of control has almost nothing useful to report.⁸⁰ The Code therefore asks whether the disease deprived the defendant of substantial capacity, meaning a capacity of some appreciable magnitude by the standard of humanity in general, so that the defense reaches a defendant whose remaining capacity has shrunk to vagrant and trivial dimensions.⁸¹ The drafters added that many advanced disorders leave rudimentary capacities of cognition and volition intact and still present inappropriate occasions for criminal sanctions.⁸² A defendant who retains a sliver of self-control is therefore not disqualified, which is the point the earlier subsection made about capacity generally, applied here to control.

The second improvement concerns timing and tempo. The word “conform” avoids the implication, often drawn from the irresistible-impulse test, that loss of volitional capacity shows itself only in sudden or spontaneous acts and never in acts accompanied by brooding or reflection.⁸³ Proponents described the choice of “conform” as a way for the rule to divest itself of the historical baggage of “irresistible impulse.”⁸⁴ A test keyed to the speed of the act would measure the wrong thing, because a disorder can produce a compulsion that the person broods over, rehearses, and plans for days, and the planning can then be part of how the disorder expresses itself. Excluding such defendants because their loss of control arrived slowly would draw an arbitrary line, since the law’s interest lies in the capacity to be restrained and not in how quickly the act followed the urge.

The same focus on capacity produces the prong’s central limit. A standard addressed to impairment of volition must distinguish between incapacity and mere indisposition, as the commentary on § 4.01 puts it, because a person who cannot conform differs from a person who will not.⁸⁵ The distinction guards against a defense that would swallow the criminal law. Nearly every offender acts on a desire that was strong at the moment, and if a strong desire or a weak attachment to the law sufficed, each of them could say the act could not have been helped. The prong therefore asks what the disease took away, and an inclination the person was able to resist but did not resist, whatever its strength, is indisposition.

The testimony in Powell v. Texas shows how this border gets litigated, although the case was decided under the Eighth Amendment and is not Code doctrine. An expert there described the compulsion of chronic alcoholism as “not completely overpowering” yet “a very strong influence,” and the defendant admitted on cross-examination that he had taken one drink on the morning of trial and had been able to stop.⁸⁶ By the Code’s line, proof that a person stopped when the situation demanded it suggests a capacity that survived, and a strong influence is not the same thing as a lost capacity. The dissent read the trial court’s findings very differently, as showing that the appellant was powerless to avoid drinking, which is the kind of finding on which a claim of incapacity rests.⁸⁷ That disagreement over one record shows that the prong turns on expert and lay evidence about what the disease did to the defendant’s ability to refrain.

Students lose this prong when they stop the analysis at knowledge of wrongfulness. A defendant who slashes throats because of a belief that God commands it, and who knows the acts are legally forbidden, probably loses under M’Naghten and under the federal insanity statute, since knowing that the acts are legally forbidden defeats both. The answer under § 4.01(1) is nonetheless yes, because the Code adds a question the older tests never ask, namely whether the disease left the defendant with substantial capacity to conform. The prong is also the most contested part of the Code test, so its availability depends on the jurisdiction. The Third Circuit in United States v. Currens used only the conformity portion of the test, reasoning that the appreciation wording puts too much weight on cognition.⁸⁸ The movement later ran the other way: after John Hinckley was acquitted under the Code test, Congress enacted the Insanity Defense Reform Act of 1984, which exculpates only defendants unable to appreciate the nature and quality or the wrongfulness of their acts and so eliminated the volitional prong from federal law, and three-fourths of the states responded similarly, most reverting to or reaffirming M’Naghten-type rules.⁸⁹ The Fifth Circuit, sitting en banc in United States v. Lyons, likewise withdrew the recognition of the volitional prong that it had given when it adopted the Code test.⁹⁰ On an exam, the prong is available when the problem supplies the Code’s text or a statute that follows it, and unavailable when the problem supplies a M’Naghten-style or federal formulation.