Merriam-Webster’s Collegiate Dictionary has it as the following: 1 a : a deranged state of the mind usually occurring as a specific disorder (as schizophrenia) and usually excluding such states as mental retardation, psychoneurosis, and various character disorders b : a mental disorder 2 : such unsoundness of mind or lack of understanding as prevents one from having the mental capacity required by law to enter into a particular relationship, status, or transaction or as removes one from criminal or civil responsibility 3 a : extreme folly or unreasonableness b : something utterly foolish or unreasonable

Don’t all of the above seem to describe a mother of five children who would systematically kill them, one by one, by drowning them in the family bathtub last June 20?

A Texas jury didn’t see it that way, and found Andrea Yates guilty of two counts of capital murder earlier this month.

Yates, 37, confessed to the drownings but pleaded not guilty by reason of insanity. After a two-week trial in which her defense argued that she did not know her conduct was wrong, a jury of eight women and four men found her guilty after only 3 ½ hours of deliberation.

Yates told psychiatrists she drowned the children because they were not "righteous" and would burn in hell if she did not take their lives while they were still innocent. That in and of itself would seem to indicate a knowledge of the nature of the actions, albeit based on her understanding of God’s law as opposed to Texas law.

But a 1999 psychiatric evaluation by physicians in Texas resulted in a diagnosis of postpartum depression with psychosis. Postpartum (following birth) depressions are not uncommon, but for most women they are transitory and pass without major incident. However, some become full-blown depressions with psychoses, which are mental derangements characterized by defective or lost contact with reality.

The medical report indicated that she had been hospitalized after attempting overdose with prescription medication, and later was under observation after her husband had to forceably remove a knife which she was holding to her own neck. Call it insanity or call it mental illness, but the woman had a history of impaired judgement.

The insanity defense dates to 1843, when Daniel M’Naghten was acquitted for attempting to assassinate British Prime Minister Sir Robert Peel. M’Naghten attempted to stalk Peel, but mistook Peel's secretary, Ed Drummond, for Peel. M'Naghten shot and wounded Drummond, who subsequently died. The evidence at trial showed M'Naghten had delusions of persecution. An insanity plea was entered with the claim that the crime was the result of M'Naghten's delusion. The facts that M'Naghten had killed in broad daylight without any plan of escape were seen as very important, as was the defense claim that M'Naghten could not distinguish between right and wrong. The jury deliberated for less than two minutes before returning a verdict of not guilty by reason of insanity.

As the result of that verdict and public outcry, a new code was adopted in Britain which also became the standard in most of the United States. Insanity was strictly defined under that code, and the delusions that the defendant suffered had to be so strong that he either did not understand his actions or was unable to appreciate their wrongfulness.

In the next century, insanity laws were expanded. A person might be found not guilty if his delusions were so strong he could not control his behavior even if he recognized others would see them as wrong.

When John Hinckley Jr. was acquitted of the attempted assassination of President Reagan in 1981 based on that definition of insanity, laws in Texas and across the country were changed to eliminate the provision allowing a defendant to claim the inability to control his conduct as insanity.

While the definition of insanity has been consistent in the dictionary, the same can’t be said for the legal system's definition. Review is needed for the process of law which would allow someone with such a history of mental illness like Yates to be sentenced to life in prison without any possibility for reconsideration if she is able to get treatment and somehow get well. And there is precedent for the legal system to make changes in the way it defines and adjudicates insanity.

Mr. Tom Mitsoff is a daily newspaper editor and syndicated editorial columnist. His web address is http://www.tommitsoff.com.