A scholarly lady (with apologies to the late Clare Boothe Luce, whose impassioned rule was that ''lady'' could be used only in such situations as otherwise would require the use of ''gentleman''), writing to The New York Times, has given useful perspective on the Catholic Bishops' Condom Issue. For those who do not follow news of Catholic bishops, or of condoms, or even of the unlikely combination of the two, what came before was as follows:

A committee of bishops, acting, so to speak, as an executive committee, last month issued a longish paper the burden of which was that Catholic schools should teach students about the uses of condoms, in order to guard against the spread of the AIDS virus. Cardinal John O'Connor of New York, when he heard about the action of the committee, issued a blast against the document, condemning it as an invitation to promiscuity. He promised that several other American bishops would join him in the weeks to come in rejecting the instrument, and in due course Cardinal Bernard Law of Boston came forward with an equally strong statement, and less emphatic rejections were issued by a half-dozen other bishops.

To the surprise of the Catholic community, what at first appeared to have happened, just after Christmas, was a formal recall of the controversial statement, pending a full ventilation of it at the next plenary meeting of the bishops, scheduled for June. But this recall was later denied. A recall of a statement issued by a committee of bishops, one gathers, would be unprecedented in the United States, and the mere hint of it suggests deep divisions. The question before the house is: What are those divisions exactly all about?

It is true that the most conspicuously liberal bishops in America, if that is the word for it, were the most enthusiastic about the condom statement -- namely, Cardinal Joseph Bernardin of Chicago and Archbishop Raymond Hunthausen of Seattle. There is an obvious temptation here to suppose that there are some bishops whose attitude is: Look, let's just be grown up enough to recognize that Catholics are of the same biological composition as Protestants and Jews and therefore no matter how much emphasis we place, in their training, on sanctioned sexual behavior, they are going to prove their fallibility 70 times seven times, and since this is the case, we may as well not have 70 times seven bastards, 70 times seven abortions, and however many more AIDS cases germinate from 490 homosexual unions.

Before the proposed recall of the committee's December declaration, surveying the apparent confusion, one wag remarked that it looked as though the Catholic Church in America was in favor of condoms except for birth control. It is such confusion that M. Cathleen Kaveny, identified in The Times as ''a candidate for a PhD in religious ethics and a law degree at Yale University,'' clarifies with exemplary lucidity.

There is, in Christian doctrine, the ''time-honored 'rule of double effect.' " Miss Kaveny gives an example:

''Suppose a newly married Catholic couple who want nothing more than to start a family discover that the hemophiliac husband has contracted AIDS through a blood transfusion. To foster the great unitive good of marital intercourse, they could use condoms without violating the teachings of Humanae Vitae {the most vigorous (1968) papal encyclical opposed to birth control by artificial methods}. If asked why they were using condoms, their answer would be 'to prevent the transmission of AIDS.' Thus the end, aim or primary effect is entirely licit.''

As far as she goes, Kaveny is clearly correct. But everyone will instantly acknowledge that the hypothetical use of the condom in the example given will fit very few married couples. What the O'Connorites are saying, in effect, is: Look, advertise the condom and its benefits, and you advertise, in effect, mechanisms by which the consequences of sinful behavior are diluted. In doing so, inevitably you increase the incidence of sinful behavior.

The Bernardinites are saying: Look, sins are bad enough, but sins that lead to AIDS bring on temporal consequences out of proportion to the sin committed; moreover, the consequences, as often as not, are visited on innocent parties. One may cavil that there is no such thing as an innocent party in male-to-male sex. Still, we ought not to be accessories to death sentences for failure to comply with Christian law. Such mortal punishment comes not only to AIDS victims but also to aborted fetuses.

It is projected that there will be a ''disputatio'' on the question in June among the bishops in private session. It's too bad there won't be any Democratic congressmen there. It would be good if somebody leaked the proceedings.