(FORTUNE Magazine) – ''Instantly procure the unexpurgated file on Judicial Activism,'' recently screeched the senior Keeping Up correspondent on the social issues desk, ''and while you are about it also arrange for the present writer's timely perusal of mortality tables published by the National Center for Health Statistics (NCHS), as the nexus between these two databases grows increasingly germane to policymakers and maybe even bookmakers.'' As you doubtless intuited, what brought on the above ululation was Supreme Court Justice William J. Brennan Jr. Lovingly saluted on the front page of the New York Times and also implicitly compared to Moses the Lawgiver in a Washington Post editorial, the Supreme Court's oldest member (at 79) had gone and given a talk at Georgetown University and come out for judicial activism. Possibly we should mention around here that this was not the way the Post saw it. On the Post's analysis, Brennan merely came out for ''common sense.'' Bill's own formulation was that the Brethren and Sister Sandra could not just sit there and support ''the values of 1789 specifically articulated in the Constitution'' but instead had to adapt to ''changes of social circumstance,'' which is the standard argument made by liberal jurists aching to reshape the world. Amazing organization, the NCHS. A treasure trove of fascinating facts about life and death. Did you know, for example, that births are not evenly distributed over the days of the week? Yes, that point was made just recently in one of the center's publications. It turns out that the most popular day (Tuesday) actually has 26% more births on average than the least popular day (Sunday). The big swing factor seems to be births via Caesarean section -- that and the widespread perception among medical professionals that the Lord created Sunday so they could play golf. They need Monday to perform tests, we infer, and they like to operate on Tuesday so that the patients can get home before the next weekend. Logical, eh? But we wander. More relevant to our judicial concerns are those NCHS tables showing percentage probabilities of death during every year of life for men and women and blacks and whites. The tables make it possible to deal quantitatively with a subject that has long been a staple of chatter in Washington: the mortality of Supreme Court justices. The subject now seems to be more fascinating than ever, with a widespread perception that a conservative Administration yearns to replace liberal jurists. Evidencing the Court's own fascination with the subject, Justice Harry Blackmun (77) gave a remarkable talk a while back in which he candidly sized up the health of his colleagues. So how many additional conservatives can the Reagan Administration hope to put on the Court during its remaining three years or so? The NCHS data suggest that the Administration is quite likely to be making some appointments. Even if you assume that nobody on the present court will retire while breathing, there is only a 21% likelihood of the whole gang making it through another three years. (The Court, second oldest in history, has an average age of 71.) Of course, it makes a difference who dies. The Court's conservatives are generally held to be Chief Justice Warren E. Burger (78), Lewis F. Powell (78), William H. Rehnquist (61), and Sandra Day O'Connor (55), and if one of them departs, the replacement would presumably not signify big change. On the other hand, the termination of either of the Court's super-liberals, Brennan or Thurgood Marshall (77), would make a huge difference, converting a centrist court into one with a clear conservative majority. The probability of at least one of them dying: 41%. If you also count Blackmun as a liberal, the probability of losing one goes up to 54%.

Idealists wondering about a totally conservative court -- all the liberals die, along with centrists Byron White (68) and John Paul Stevens (65) -- should know that the odds against this event are around 10,000 to 1. About the same as Brennan coming out for judicial restraint.