The battle over John Errol Ferguson's execution is not about who he is — a cold-blooded killer — but about who we are as Floridians. Ferguson is severely mentally ill and has been that way for more than 40 years. His execution is on hold while his mental state and the legal standards for killing someone who is mentally ill are being argued in federal court. The state and federal standards are in conflict, and the more reasonable federal standard should prevail and prevent from being executed a man who has raging hallucinations and thinks he's the Prince of God.There is nothing redeemable about Ferguson or his heinous crimes. In 1977 he participated along with two accomplices in the massacre of six people during a home invasion in Carol City while looking for drugs. On his own Ferguson murdered two teenagers six months later, raping the girl. Ferguson, now 64, is a deranged, dangerous killer who should never have been out on the streets. As far back as 1965 Ferguson had been found to suffer from "visual hallucinations." In the early 1970s, he was sent to state mental institutions where doctors diagnosed him as "grossly psychotic" and someone who doesn't "know right from wrong." He was found to be paranoid schizophrenic, delusional, explosive and aggressive. And in 1975, a doctor wrote presciently, "This man is dangerous and cannot be released under any circumstances." In less than a year, Ferguson would be free.Ferguson's lawyer, Christopher Handman, is now in a legal race to save the mentally ill man from execution. Only a last-minute reprieve by the federal courts prevented his execution last month. The 11th U.S. Circuit Court of Appeals will review whether the proper constitutional standard for executing the mentally ill is being applied, with briefings scheduled this month.Florida is embracing an interpretation of competency for execution so pinched that it would virtually extinguish limits on executing the severely mentally ill. The state says Ferguson is aware that he is being put to death and that he committed murder, and is therefore competent to be executed. A trial judge in Bradford County accepted this view, as did the Florida Supreme Court, which failed to block the execution. But Handman persuasively argues that the standard of competency established by the U.S. Supreme Court in a 2007 decision requires a rational understanding of the reason and effect of the execution. And since Ferguson is floridly delusional, believing that, as the Prince of God, he is being executed so he can save the world from communism, among other paranoid delusions, he cannot rationally connect his crimes to the punishment or perceive the finality of execution.An objection to Ferguson's execution by Laurel Bellows, president of the American Bar Association, says law and tradition have long held that mentally ill offenders be treated differently. Now the courts have to uphold those humane standards.