TO MOST OF US the term "infanticide" is an anachronism. Except perhaps for the few widely publicized sensational tales of psychotic parents or arrant child molesters murdering helpless children, the term connotes the second most common pre-twentieth century method of birth control. (The first, of course, was celibacy.)

Between 1750 and 1850, the population of Europe doubled. The population might have increased by considerably more had certain checks on its growth been absent. Of course the major checks were a variety of natural human phenomena: famine, disease and war. And when Malthus warned that population growth would proceed at a much greater pace than the means of subsistence, he cited these as the otherwise absent limiting forces.

However, there were several artificial practices at work. Infanticide especially in its passive form--abandonment--was a widespread practice.

The practice is a sort of selective method of birth control. And it is not so illegal at that. Nobody knows for sure how many deformed or "undesirable" newborn infants conveniently "die" immediately after birth.

No doubt the mothers of many such infants are simply and directly told by their doctors that the children they carried for nine months were stillborn. The doctor thus participates in mercy-killing. Alas, the merciful physician--possessor of the "God syndrome"--giver and taker of life.

Presumably such murders are performed to eliminate the burden the deformed infant would impose on the parents and other children in the household. One still wonders about the source of the doctor's clairvoyance, his amazing ability to foresee the wishes of the parents.

And then, of course, there are the many instances in which the parents themselves are the source of that authority. Some situations readily lend themselves to a passive mode of murder. The most interesting case studies are those that involve children born with Down's Syndrome, popularly termed Mongolism because facial characteristics of those afflicted frequently resemble Mongoloid racial features.

The case of the Mongoloid child born with a physical defect that may be related to, but is separate from, the syndrome itself, is worth examining. (Down's Syndrome is the possession of an extra chromosome, usually on the twenty-first pair.) The physical defect can be corrected by surgery, but the Mongolism itself remains irreversible. Parental consent is, as usual, required for the corrective surgery.

The parents deny consent for the operation. Now the issue is whether the courts should appoint a legal guardian who will give consent for the operation. Clearly, if the child had been "normal" the court would declare the parents negligent, and appoint an appropriate guardian. Over the years, the courts have acted thus in cases involving normal children.

PERHAPS THE MOST common examples of the courts ruling this way with regard to normal children are those in which Jehovah's Witness parents refuse consent because their religion forbids transfusions. The courts have traditionally overridden the parents' religious scruples and ordered the operation in the best interest (and to protect the right) of the innocent child. The court would not rule in the case of an adult of sound mind refusing consent to an operation on himself.

Yet, such cases are complicated by the very nature of the parents' refusal for consent. That is, the decision has implicit overtones with regard to the questions of church vs. state supremacy and rights assured by the First Amendment.

For some reason, however, the issue of the state's extension of guardianship to the infant who is not "normal" becomes more complex, although the courts have consistently declined to explain their apprehension. Courts have handed down both positive and negative decisions with regard to guardianship where surgery is required for the Mongoloid infant to live. Until five years ago, most states declined to appoint a guardian for such a child. In more recent years, however, the courts have tended to reverse themselves, and most will now remove jurisdiction of the child from the natural parents.

It is not at all clear that the Mongoloid child is a burden on himself. In fact, most evidence suggests that such a child, whose IQ is usually far below the norm, is happy unto himself, for he remains unaware of his handicap. Therefore, if he is a burden on anyone, he may be on his parents and siblings.

Clearly there is a financial burden for the parents, since most public schools consider Mongoloids only marginally capable of coping with a classroom situation, and therefore deny them entrance. Most institutions contend that these children are at best merely "trainable" or "educable." However, it is of particular interest that no single religious or socio-economic group has a monopoly on couples who refuse consent for necessary surgical correction in such cases.

Of course once the state has in essence ruled that the child should live, it has assumed responsibility for the child. The chances are more than likely that the infant will end up in an institution where the chances for full development of his potential are less than slim. Some would ask, given the parents' rejection of their own child, "Wouldn't 'it' have been better off dead?

INFANTICIDE, THEN, represents a more certain method of selective birth control than the combined pre-natal actions, anmiocentesis and abortion. The parents can see their creation and decide whether it is worth keeping. However, this infanticide, an example of euthenasia, is at present deemed criminal homicide, despite the motive of mercy. Most legal experts dispel claims that passivity is not as culpable as a positive act of murder. They contend inaction is tantamount to action when there is a duty to act, and most moralists would agree.

Paul A. Freund, Loeb University Professor, notes that the analysis of this infanticide-euthenasia discussion ultimately poses the question, "If one is, without fault on his part, a threat to the well-being of others, may those others in good conscience remove the threat to enhance their own lives and the lives of others dependent on them?"

Clearly, this is not precisely analogous to the case discussed here. As pointed out, the Mongoloid is not a danger of any sort to the people around him. He is an individual with a happy disposition, responsive to loving care. Nevertheless, the case is one in which people are driven to sacrifice life in the interest of the well-being of the survivors.

Freund neatly explains the crux of the issue: "Due process of law, and equality of right to live, are afforded not merely for the sake of the potential victims, but for the sake of the judges and of society, to save us from the agony and absurdity of making ultimate judgments of worth, of assuming the role of a god on the Day of Final Judgment.

"The ultimate question, then, is one of social responsibility for maintaining conditions under which private morality will not be confronted with harrowing choices that are avoidable