TOMORROW MORNING at seven, John Arthur Spenkelink and Willie Jasper Darden Jr. will die in the electric chair in Florida. That, barring an 11th-hour reprieve, is the situation at this writing, though this is one circumstance when we would be more than pleased to be overtaken by events.

Gov. Robert D. Graham signed the death warrants last Friday - a power that, under Florida law, is given the governor alone. If Gov. Graham had wished to grant clemency, at least three members of the seven-member Executive Clemency Board would have had to concur. Three board members have in fact indicated that they would have voted for clemency: "My God, Man," said one. "We have over 130 men in there. We can't execute all of them." A practical argument, if not especially philosophical.

But what philosophical argument is to be made in this case, and in the others like it that spring up from state to state, and from time to time, like warning lights on a war map? In 1976, the U.S. Supreme Court decided that the death penalty "does not necessarily violate the Constitution." All such a decision could accomplish was what it did - to throw the matter back to the individual states, which in turn tried to formulate statutes that would make the death penalty less arbitrary. In Maryland, a new death penalty statute that went into effect last July indicated that the death penalty could be imposed on someone who commits murder while also committing "rape or a sexual offense in the first degree." In the recent case of murderer William Joseph Parker, much was made of the fact that the phrase is ambiguous without a comma after the word, "rape", which allowed Judge Howard S. Chasanow to give Parker a life sentence. Judge Chasanow's position was more humane than Gov. Graham's has seemed to be. But comma or no comma, his ruling is just as arbitrary.

The point - as if it must be made over and over again - is that no man, or judge, or governor is God. And the decision of life or death is always bound to be arbitrary and capricious, no matter how carefully or carelessly statutes are written, or how many commas are left out. Why posit the number 3 as necessary to grant clemency in Florida? Why set up a seven-member board, except that the number 7 has long-standing cosmological and superstitious significance. Why empower a governor, so removed from the facts of a case, with the decision on pulling the switch? And why do some states decide to use the switch, and others not? Is this a states-rights issue? Are the separate states in their separate wisdoms to be considered different from the country as a whole in the matter of life and death? Does Florida need more vengeance than New York?

There is a terrible nonsense to all this, and a sickening sense of futility. In Florida, Mr. Spenkelink's mother joins 300 other protestors at the governor's mansion. The American Civil Liberties Union and the Florida Clearinghouse for Criminal Justice scrape frantically for some last-minute brainstorm. The condemned wait in their cells. And the governor appears adamant. For what? If this civilization is to last another couple of hundred years, it will look back upon such scenes with the same unamused horror with which we look back now upon the treatment of the insane in the 18th century, and the Salem witches.