To begin with this line of inquiry, we must recognize the importance of the concept of mens rea in our legal system. Mens rea is a Latin term meaning “guilty mind”. It is a cornerstone of American justice, and reflects deontological though the question of intent. “Crimes are defined by their 'elements,' which always include a prohibited act and in most cases a mental state, a mens rea, such as intent. “ (Morse & Hoffman, 2007, p.1074) The basis of the insanity defense is that the insane can not have mens rea as there is an incapacitation of agency. However, there are several other legal contexts in which the lack of mens rea has been raised; “heat of passion”, intoxication, mental retardation, and the criminal responsibility of juveniles. There have been legal precedents in which lack of mens rea does not protect the offender from criminal liability; in the case of intoxication, Montana vs Egelhoff and in the many cases of juveniles being tried as adults due to the severity of their crimes. As it becomes clear that mens rea is important to our idea of justice, it just as clear that there limits to claims of a lack of mens rea in criminal defense. Mental illness is also limited in these claims; “mental disorder produces crazy desires or crazy beliefs about reality,but it virtually never prevents a defendant from meeting the law's criteria for intention, knowledge, conscious awareness, and other mens rea terms.” (Morse & Hoffman, 2007, p.1087)
Next, an examination of utilitarian and retributive theories do not show compelling reasons to consider the execution of the insane as immoral. This is more apparent for utilitarian theory, which focuses solely on the consequences of actions and the weighing thereof, but it is not so clear regarding retribution theory. To begin with, “the nature of retributivism is deeply contested. No particular account should be regarded as canonical; philosophers of criminal law use this label in countless different ways.(Husak, 2012, p.450) Husak does contend that “Despite their considerable differences, all desert theorists place the principle of proportionality near the heart of retributive justice. “(2012, p.453) Even so, how proportionality is measured differs. One view of retributive thought holds that “the insane prisoner does not possess the ability to understand the reasoning behind his punishment, therefore stripping the retributory effect of the punishment” (Gogna,2012, p.16). Hollander-Blumoff expounds on this idea, “There are several basic tests of insanity, all of which rely to some degree on a conception of the sane individual’s ability to control his actions. The M‘Naghten test states that a person is insane if, at the time of the act in question, he did not know the nature and quality of the act or did not know that the act was wrong. This means that individuals who know what they are doing, and that their act is wrong, are not insane. This test tracks a retributivist account of self-control: we only punish those who could have chosen not to do wrong.”(2012,p.515). One the other hand, retributive theory insists that social relationships be restored; “Since crime is defined as the violation or disturbance of the "right" relationships in the community, the goal of the retributive theory of justice is to reconcile these relationships. Reconciliation is accomplished by making an offender "pay" for the disturbance his or her conduct has caused.”(Starkweather1992 p857). “Kant states that the act that the person has performed “is to be regarded as perpetrated on himself” “ (Murtagh, n.d., para. 11) Thus, as some retributive thinkers morally justify a claim an exemption to mens rea based on insanity, others posit that such a defenses does not meet the basic definition of retributive theory. Reflecting it's disparate nature, there is no overall moral justification of the insanity defense from a retributive viewpoint.
On the other hand, utilitarian theory presents several specific opportunities for opposition to the idea. The first is that the qualification of insanity is not easily judged; “Probably the most widely used definition in the United States, and perhaps in the world, is contained in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders. This document admits,however, that "no definition adequately specifies precise boundaries for the concept of 'mental disorder'” (Morse & Hoffman, 2007, p.1082) This presents a lack of certainty that justice, a beneficial consequence for the public good, can be attuned. Indeed, considering that intent is not a factor of utilitarian thought, one utilitarian argument is that the concept of mens rea doesn't apply at all; “the mens rea issue is entirely distinct from the legal insanity issue, even if precisely the same evidence would be relevant to adjudicating both claims. People with mental disorder are not automatons; rather, they are agents who act for reasons. Their reasons may be motivated by distorted perceptions and beliefs, but they do form intentions and have knowledge of what they are doing in the narrow, most literal sense” (Morse & Hoffman, 2007, pp.1096-1097) Morse and Hoffman continue to provide argument for the idea that the consideration of intent is not necessary to provide justice, especially in the case of the insane; “No matter how limited an insanity defense may be, some defendants will have been so grossly out of touch with reality at the time of the crime that an excuse is warranted because their mental disorder, as in our example of the deluded self-defender, interferes with their rationality even if it does not interfere with their formation of mens rea. It is precisely because of this category of defendants that mens rea alone cannot do the work necessary for a morally coherent system of criminal responsibility.” (Morse & Hoffman, 2007, pp.1119-1120). Another argument that utilitarians would use in favor of the death penalty for a criminal offender suffering from a violent mental illness, and thus touching on Brunsvold's surface issue of medical treatment, is the continuing potential of danger presented by such an offender; “The Eighth Circuit majority seems to believe that since Singleton became dangerous when not taking medications on one occasion, he would always be-come dangerous when he stopped them”(Zonana, 2003,p.375)
Beyond the concepts of utilitarian and retributive thinking, there are other moral questions regarding the use of the insanity defense. Due to the fluid definitions of insanity as applied from court to court and psychiatrist to psychiatrist, Morse and Huffman make the point that there is not an objective level of insanity,“unlike the mens rea inquiry, legal insanity is a legal and moral policy judgment, not a particular empirical fact.”(2007, p.1119) and they continue this line of thought, “precisely because insanity is a moral construct and not a scientific one, we cannot abandon it to the scientists, especially scientists who, as we discuss below, misguidedly reject the possibility of individual responsibility tout court”( Morse & Hoffman, 2007, p.1119). Morse and Huffman follow that assertion by examining the motives involved; “Some people, including many neuroscientists, think that these discoveries are leading inexorably to a mechanistic, deterministic view of the brain, and thus to a mechanistic, deterministic view of human behavior in which conscious intentionality plays no role”(Morse & Hoffman, 2007, p.1133)
In conclusion, the warden, the corrections staff, and the lawmakers need to contend with the thought that there is more to the morality of the insanity defense then simply a possible, and yet hard to prove, incapacity for mens rea. In the first place, although mens rea is crucial to American jurisprudence, there are exceptions to the requirement of mens rea in other contexts of incapacity of agency than insanity. Secondly, morally speaking it has no ground in utilitarian considerations. Third, retributive theory both supports the insanity defense and prohibits it, but retributive theory is diverse to begin with. Finally, the use of the insanity defense should be a moral issue rather than an issue decided upon a question of assumed but unprovable “objectivity”.