hat a simple world he portrayed. A world divided into good and evil, godless and god-fearing. In his sermon to the converted last week in Orlando, the presidential evangelist asked only the easy questions and gave only the simplistic answers.

He aimed the multiple-choice mentality at war and peace, the United States and the U.S.S.R. and even at the dilemma of infants born with birth defects. He reduced this tragic moral issue to a question of "infanticide" and then offered an answer full of regulations and laws.

But real life doesn't divide as easily as politics, and real problems aren't resolved as simply as speeches.

For nearly all human time, nature determined the fate of most handicapped infants. Now the medical world has gained the skills to extend lives that were once doomed.

Today, many handicapped and brain-damaged children can be rescued by simple and sophisticated treatments. Low birth-weight babies, the pre-premature in the limbo between miscarriage and delivery, increasingly join the ranks of the "miracle babies."

But with our new skills come new conflicts. We are not talking about "infanticide," the deliberate killing of infants. We are talking about more subtle troubles: how aggressively do we want doctors to intervene? To save what kind of life? Who has the right to make these decisions: parents, doctors, legislators?

The cases that were once kept privately in the closed offices or hospitals are now out into the consciousness of the public. We regularly hear horror stories, competing horror stories, about infants born with instructions to "let die" and infants who were "saved" for tortured months of sophisticated treatment.

Last spring, as Reagan cited in his sermon, a Bloomington, Ind., couple refused permission for an operation that might have prevented the death of their Down's syndrome child. The baby, instead, starved. An Indiana court upheld the parents' right to decide.

In another case, documented in a new book, "The Long Dying of Baby Andrew," Robert and Peggy Stinson watched helplessly for six months as medical people prolonged the painful death of the tiny, tiny son who was born 16 weeks premature, weighing 1 pound, 12 ounces.

The president and others have called the decision in Indiana an "attack on the sacredness of human life." Peggy Stinson calls the use of "heroic and experimental technology" in her son's agony "a moral outrage showing callous disrespect for the sacredness of human life. . . ." As his son lay dying, Robert Stinson saw a magazine article entitled, "Doctors work miracles to save tiny tyke" and pondered his own saga: "Once again, tiny tyke dies slowly as doctors' treatment destroys lungs and brains."

These two are just examples of the intense, subjective, case-by-case moral and technological complexity of this issue. Would I have refused surgery to the baby in Indiana? No. Would I have condemned Baby Andrew to this travesty of caretaking? No.

But what this administration has done, as Reagan told his parishioners, is to issue blanket regulations to hospitals stating that it is illegal to fail to "feed and care for handicapped infants." It has, moreover, set up a 24-hour, toll-free hotline for informers. Now it is also proposing legislation.

What will a requirement to "care for" handicapped infants mean? A simple treatment for a mildly retarded infant? Elaborate heart surgery for a profoundly brain-damaged baby? Aggressive no-holds-barred heroics for every infant like Andrew? An intensive-care unit full of the hopelessly saved?

Does it mean that we will take the caretaking decisions out of the hands of parents and doctors and into the hands of the government? How will it effect the medical personnel whose judgments are already colored by their own fear of lawsuits?

This is a classic case for deregulation, not new regulation. One flat rule written in Washington will create chaos and increase misery when applied to hundreds of special stories. The Great de-Regulator should know that.

Surely there is a need to develop a consensus on ethical guidelines in dealing with infants who have birth defects. But there is no room for a rule or law that ignores the muddiness of human and humane reality.