Should You Be Skeptical of The Insanity Defense?

From the lecture series: The Great Ideas of Psychology

By Daniel N. Robinson, Ph.D., Oxford University

There’s a litany of research suggesting profound alterations in emotional life associated with disturbances in the brain. Of course, this raises some acute philosophical questions.

justice and law concept.
(Image: By everything possible/Shutterstock)

Brain Damage and Behavior

It’s known that patients with right hemisphere damage in the brain will not laugh at jokes, whereas damage to a corresponding part on the other side of the brain doesn’t have quite that effect.

It’s also known that patients with amygdalas that aren’t functioning properly—that are either damaged or lesioned—will fail to appreciate the emotional quality of the facial expressions of others.

In fact, there’s an entire litany of clinical and research findings suggesting profound alterations in emotional life attendant upon disturbances in the brain and the nervous system in general.

This is a transcript from the video series The Great Ideas of Psychology. Watch it now, Wondrium.

Of course, this raises a question about the extent to which anyone is actually responsible for what one does in emotional states, in states of intense anger. The courts gradually, and kicking and screaming, have more or less begun to catch up with the data—the clinical findings, the research findings and theory—and so we find contemporary adjudicative processes involving the insanity defense now weighed down with all sorts of medical, physiological, and neuropsychological testimony.

It is something that very often amuses when it doesn’t deeply concern the average citizen, and it seems to be a topic worthy of our attention.

Learn more about criminality as a pathology instead of a moral quandry

The Insanity Defense

Let’s begin by saying a few things about the insanity defense itself and how the law has traditionally understood the exculpatory power, the power of forgiveness, contained in such states as irresistible impulses and intense emotional states.

The first thing to keep in mind, particularly if you are a skeptic about the insanity defense, is that there is no time in the recorded history of Western jurisprudence when there has not been an insanity defense. You will find it as early as the homicide laws of Draco in the ancient Greek world. You will find it on Rome’s 12 tables. Rome’s 12 tables includes a provision that if somebody, because of insanity or madness, is squandering the family fortune, someone else can be appointed to preside over the management of the family affairs. So this has been a fixed chapter in the history of jurisprudence from the very outset; and, of course, it has to be.

The first thing to keep in mind, particularly if you are a skeptic about the insanity defense, is that there is no time in the recorded history of Western jurisprudence when there has not been an insanity defense.

The very concept of law presupposes the citizen’s ability to control himself and comport himself according to the requirements of law. That is, the very concept of law assumes that a being has sufficient rationality, sufficient self-control so as to be able to regulate his conduct according to the law’s requirement. Punishment then is imposed on those who fail to do so.

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But if, in fact, one is so lacking in mental power—non compos mentis means literally “no power of mind”—if one is profoundly retarded, if one is hopelessly insane, then one lacks the requisite powers to conform oneself to the requirements of law. In the very concept of crime and punishment—crime being mens rae—there has to be power within the mind to frame the evil act. The very concept of crime, the concept of punishment, the concept of law itself presupposes those rational and emotional attributes that render one fit for the rule of law.

What Criteria?

The issue—to the extent that there is an issue—has never been about whether there should be an insanity defense. The issue has always been what criteria have to be satisfied to qualify one as insane for purposes of law; and these criteria have had a quite shifting history.

If we go back to the words that were used in ancient Rome to cover insanity, at least as judges would regard a defendant as insane, the words we confront are words like furiosus, fanaticus, non compos mentis, idiotus. What these words are seeking to define is one so bereft of reason as to be a furiosus in the sense of a wild beast—an absolutely unconstrained creature of the wild beyond the reach of reason.

This came to be known as the “wild beast” criteria, and it remained in place until well into the 18th century. That is, from the ancient Greek and Roman times to well past the time of the first Queen Elizabeth, the grounds of forgiveness at law included someone so destitute of reason as to be really beastlike.

Image of "A Rake's Progress" by William Hogarth. A depiction of Bethlehem hospital, the world's oldest psychiatric hospital
“A Rake’s Progress” by William Hogarth. A depiction of Bethlehem hospital, the world’s oldest psychiatric hospital (Image: By William Hogarth/Public Domain)

The Trial of Edward Arnold

The earliest trial for which we have a complete trial transcript involving the insanity defense was the trial of Edward Arnold in 1723, a trial in the history of law referred to as Rex v. Arnold. Without going into too many details, it is safe to say that Edward Arnold was a strange fellow.

His sister testified during the trial that as a child, when Arnold would engage in some sort of disagreement with the family, it was not unusual for him to attempt to burn down the family house.

His barber reported that when he would come in for grooming, he’d tilt his head back and tell the barber to “cut my throat.” Arnold was a man of manifest eccentricities, no doubt about it.

What brought him before the bar of justice was that he made an attempt on the life of Lord Onslow, a nobleman, and this on the grounds that Lord Onslow had been sending imps to disturb Arnold’s sleep. He only very lightly wounded Lord Onslow, but nonetheless the law at that time called for the maximum penalty in cases of attempted murder. You didn’t execute people merely because they were good shots; if you attempted to kill someone at all you were done in.

When Robert Tracy, the judge in this case, instructed the jury, he reviewed for them the historic insanity defense going back to Roman standards and through to the British common law understandings of insanity. Then he said to the jurors these words, after establishing that there must be an insanity defense, “not to fret over that, the very concept of law entails as much.”

And then, “But it is not every idle humor of a man that spares him the burden of his crime. It must be one so destitute of reason as to have no more rational power than doth an infant, a brute, or a wild beast.” Here was a repeat, at the beginning of the first quarter of the 18th century, of the wild beast criteria.

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The Trial of James Hadfield

This was turned around in a famous 1800 trial, the trial of James Hadfield, in which Hadfield was represented by the greatest trial lawyer in the United Kingdom at the time, Erskine, who would later go on to become Lord Chancellor.

Incidentally, Erskine was a very interesting person, and he defended Thomas Paine in absentia when Paine was declared persona non grata in Britain for authoring the work Rights of Man. Although Erskine lost that case and Paine was convicted of seditious statements, his defense of Paine is one of the great defenses of freedom of ideas and freedom of expression in Western history. Erskine would die a pauper, by the way.

By the time of his attempt against the life of the king, he had taken up with a barrister named Trulock and the two of them would exchange roles, whereby one of them would represent Satan and one would represent God.

Hadfield’s situation was a hopeless one. He was a man who had been wounded in battle while serving the very king he was now charged with attempting to kill. The charge against James Hadfield was that he made an attempt on the life of George III.

It is worth nothing that by the time Hadfield was doing this, attempts on the life of George III were becoming something of a national sport. Hadfield had sustained horrible injuries while at war, and those who were present at the battle in which these injuries were sustained said that—and those with an aversion to graphic violence might skip the next sentence or two—the sword wound to his neck was so extreme that as his torso turned, the head would not move in place.

He was then hit with the butt of a sword and the wound was so deep that one could see the convolutions of the brain. By the time of his attempt against the life of the king, he had taken up with a barrister named Trulock and the two of them would exchange roles, whereby one of them would represent Satan and one would represent God.

Who would be responsible for doing God’s work in the world? Who would take up against this reigning monarch and create a climate in England that would host the return of Jesus Christ our Lord and Savior?

Then one fateful day Hadfield got a brace of pistols and went over to the theater at Drury Lane. He waited for the king and the king’s entourage, and then he fired, wildly missing the king. But of course, the nation itself is the king and Parliament, and so an attempt on the life of the king is an act of treason for which the penalty is the maximum penalty.

Erskine mounted a wonderful spirited defense, one of the great tour de force performances in the history of legal defenses. Erskine complemented the prosecution for summarizing the history of the insanity defense, and says, of course he’s told you all the things you’re supposed to know. He’s told you about the furiosus and the fanaticus and non compos mentis, and most importantly he has summarized the reasoning in Rex v. Arnold, the wild beast criterion. Then Erskine goes on to say, if you were to accept these criteria, then you must wrestle with the fact that no one answering to these criteria has ever existed in the history of the world.

Portrait of King George III by Allan Ramsay 1765
King George III – the target of James Hadfield’s failed assassination attempt (Image: By Allan Ramsay/Public Domain)

What Erskine wanted to make clear was: If, in fact, you had no more rational power, than an infant, a brute, or a wild beast, you couldn’t commit a crime, that no one answering to the description of insane could so much as load a gun. Erskine pointed out that, although these understandings had a place in their time, the jury must not be held hostage to antique ignorances.

He argued that science knew much more, medicine knew much more, about insanity than the ancients could have known or that anyone could have known even 50 years before the trial in 1800.

So we begin to see a tradition being put in place. The insanity defense must be reconsidered in light of recent knowledge, and of course, in the trial of Hadfield.

Erskine had two medical experts, one of them a Dr. Crichton, who had recently written a treatise on criminal insanity and on the laws that pertain to insanity, which put Erskine in a position to change the law within the British context.

Learn more about the nature of sanity and insanity 

He overturned an earlier precedent by introducing a concept that he successfully impressed upon the jury as being the right standard in trials of this kind.

He said, what we now know, that the ancients couldn’t have possibly known, that until recent times wasn’t known, was this: one true mark of insanity is delusion, and if you are satisfied that at the time he took the act against the king, the defendant was deluded as to matters of fact, you must find him not guilty by reason of insanity.

More, if the delusion is of such a nature that you are satisfied were its contents true, you then must ask yourself: How would the law deal with such a case? Suppose, in fact, Hadfield was fulfilling commandments given to him by our Lord and Savior, Erskine asked, is there a court in the realm that would convict a man for doing what is nothing less than the will of God?

So the jury was to ask themselves; first, does the man suffer from an insane delusion creating within him motives irresistible? And secondly, if you are satisfied that he does suffer from a delusion, then you ask yourself this: In case the contents of that delusion are true, what would the law’s position be in regard to the act the defendant has been charged with?

Erskine was very, very influential in having the law regarding the very nature and mark of insanity understood in a new and different light. Hadfield got off with this defense; and in 1800 the Insane Offenders Act was passed by Parliament which meant that Hadfield could be sent to a place reserved for those who were criminally insane.

Heretofore, persons found not guilty by reason of insanity would simply walk out of the courtroom and very often proceed to do the very things that they had been brought in and tried for in the first place. The new legal understanding for insanity was accompanied by facilities set up to warehouse the criminally insane.

Common Questions About the Insanity Defense

Q: How many types of the insanity defense exist?

There are considered four primary types of insanity defense: the M’Naghten, irresistible impulse, substantial capacity, and Durham.

Q: Is the insanity defense successful?

According to research, the insanity defense is rarely used and has around a 26% success rate, so it is not very successful.

Q: Are there any states that won’t allow the insanity defense?

The insanity defense is denied by four states: Idaho, Utah, Kansas and Montana.

Q: What is the result of a positive use of the insanity defense?

When the insanity defense is used successfully, the defendant could be completely not-guilty. If the defendant is shown to be responsible for the crime, then the defendant would be admitted to a psychiatric hospital.

This article was updated on 12/20/2019

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