Few controversies more starkly divide Americans than what to do about abortion. Opponents of abortion, rejecting the present situation as a hideous mockery of God's law, long for a more chaste, humane future, full of men and women who will revere life and, incidentally, think twice before conceiving it. Abortion supporters, on the other hand, conjure up a nightmare vision of possible years to come: women butchered, degraded, forced into the involuntary servitude of undesired motherhood. Each side believes we can reach those very different futures by a single route: once again outlawing abortion.

A simple wave of the legal wand will supposedly take us back to the old days. We'll find ourselves, according to one view, once more in a time when nice girls don't, when family life is sacred and when children respect their parents. Or we'll suffer once again, according to the other view, the fear and dread of the days when unwanted pregnancy meant the squalid back-alley abortionist, the coat hanger, the very real risk of death.

But in fact neither of these views accurately represents what would happen if abortion were outlawed tomorrow. We can't go home again, in part because home was not exactly the way we remember it, and in part because it's changed while we were away.

The halcyon past of the antiabortionists' fond recollection quite simply never existed. Until 1973, no one ever took an accurate count of how many abortions, illegal and "therapeutic," took place. But in 1936 Frederick J. Taussig estimated the number of abortions at more than half a million annually, and for the next 37 years, experts accepted that as a realistic, or even conservative, estimate.

There never was an abortion-free golden age. Today's annual rate represents at most a tripling of the rate in former years.

Despite its prevalence, abortion in those days often meant some big risks. Many illegal abortions were done on the sly by well-trained physcians, but falling into other hands often meant perilous probing of the delicate uterine walls by untrained, unskilled and often unscrupulous quacks.

Some women successfully aborted using the proverbial coat hanger; many others died trying. Gynecology wards in those days housed a whole class of patients that has since vanished: the infected, gangrenous survivors of botched illegal abortions.

If abortion were outlawed, it can't be denied that obtaining an abortion would again become much more difficult than it is today. Once more women (and the men involved) would know the frantic hunt, the degradation, the often exorbitant costs of obtaining a service on the black market. But the physical dangers would almost certainly be much smaller than they were.

In the 12 years since Roe v. Wade, abortion technique has taken major strides and, despite what the law may say, medical progress is irreversible.

Until the early 1970s, the most prevalent method of abortion, both therapeutic and illegal, in this country was dilation and sharp curettage. The mouth of the uterus was opened, and the sides manually scraped out with a spoon-shaped instrument called a curette.

Only a small number of people knew how to do it, and learning it meant a long, formal training unobtainable by a non-physician. Few illegal abortionists learned a safe procedure.

But after a technological revolution in the early 1970s, the great bulk of abortions (and nearly all those before 12 weeks) involve the much faster, safer, and less traumatic vacuum aspiration method, which uses a specially designed electric pump attached to a flexible tube to empty the womb. And it requires much less skill of the practitioner.

Hundreds and hundreds of vacuum machines now exist in this country. Thousands of people know -- or could quickly learn -- how to operate them safely and effectively, and would continue to know regardless of changes in the law.

Also, naturally occurring chemicals known as prostaglandins have been developed, and are widely used, to bring on late abortions.

Dr. Bernard Nathanson, a former pioneer in legal abortion, suggests that if abortion were ever outlawed, a black market in prostaglandin suppositories could easily spring up. Using these, pregnant women could "start" an apparent miscarriage, and then present themselves to doctors or hospitals, who could not prove the abortion was induced and would, in any case, have to see the woman safely through it.

And so, even if the law should change, the coat hanger would remain in the closet. Hundreds of thousands of American women would still abort each year, as they have throughout this century and the last. But now thousands of well-trained, experienced and sympathetic medical personnel -- many of them strong feminists and veterans of the struggle for legalization -- would be available and equipped to run the machines. Thousands more basement and garage chemists could easily formulate suppositories out of perfectly legal chemicals.

America has repeatedly learned to its sorrow the futility of laws forbidding people to buy what they deeply want. And in this case what they want would even be safe.

Outlawing abortion would deprive women of a right that most now approve and value (even if they may not all act on it). It would also enrage and offend many of both sexes, and impose the religious and moral beliefs of some on others who do not share them. But even less than in years past would such a prohibition prevent women from obtaining abortions. The moving finger of technology has written, and there is no going back to anyone's fantasy past.