The collapse of Douglas Ginsburg's Supreme Court nomination is being widely depicted as the consequence of an accidental, regrettable, somewhat immature hang-up that our society has about drugs. My colleague Bob Kaiser perceives a collision of cultures: the reality of widespread drug usage versus ''our puritan, often-hypocritical moralism.'' Another colleague, Henry Allen, describing marijuana as fashionable and benign, detects in Nancy Reagan's just-say-no appeal ''the tone of a Maoist commissar advocating the extermination of flies.'' A Newsweek poll reports only 26 percent of Americans think Ginsburg should have been disqualified for smoking the stuff.

Such words and numbers announce something interesting, if not exactly novel, about ourselves, and I appreciate the cultural and political insight reflected in them. But I am also aware of a whole other area of concern that does not seem to have been reflected in the public discussion so far at all.

It is what I, being a parent of children who have passed through high school into or beyond college, feel is the essential consideration with which this discussion must finally come to terms. It is: kids and drugs.

There is a part of me that is ready to see drugs, especially marijuana, as a ''cultural'' phenomenon and that summons up from me a display of worldliness and sophisticated toleration for different life styles.

But there is another part of me that tenses at the difficult choices that the drug scene forces upon young people and that rises in anger and distrust at any casual dismissal of drugs as simply a cultural or generational ''issue.''

I observe that the people who talk about drugs in this way tend to exclude entirely their darker side: the lives they waste, the crime they spawn, the suffering they inflict. Instead, they convey, usually without examining what they are doing, that there are two drug worlds. One of these worlds is safe, clean, pleasurable, sociable, condoned, tittered about, winked at, a world of limits. The other is, well, often as not the other drug world is simply not on their screen: they do not think about it and they accept no responsibility for it.

It is being widely observed now that the dangers of marijuana, and the certitude with which these dangers are visited upon users, are much exaggerated, and that it is not automatic or even likely that a young person's use of marijuana leads to use of more dangerous substances. But so often these cautions, reasonable enough in themselves, come unaccompanied by the admission that marijuana does carry some risks, as a substance and as a gateway to other substances.

I am aware that some people, addressing their children on this issue, go the instill-the-fear-of-God route and others take to the path of documentation and argument. In either event, the whole effort is undermined by attitudes of easy tolerance for an activity that remains, after all, medically questionable and illegal. And nothing contributes more to an attitude of easy tolerance than the demonstration that violations -- violations of drug laws, health standards, moral codes -- are accepted, painless, free of cost.

It would have been unforgivable if a Supreme Court nominee, no kid but someone who was still smoking as a law professor in his thirties, had not been forced to withdraw. Let us not be diverted by sympathy for Ginsburg's lost opportunity or by the extra burden the example of his misfortune puts on the career prospects of other achievers. For him to have avoided paying a price would have undermined the crucial moral message that all parents try to transmit to their children: your acts have consequences.

Nancy Reagan declares that ''each of us has a responsibility to be intolerant of drug use anywhere, anytime by anybody. Every one of us has an obligation to force the drug issue to the point it may make others uncomfortable and ourselves unpopular.'' Nancy Reagan knows the enemy when she sees it: the enemy is not simply drugs but a climate in which social and peer pressures overwhelm individual judgment. She takes a stand that draws the hisses of the hip, and I salute her for it.