THE SUPREME Court has just heard arguments in a difficult church-state separation case. At issue is a federal law that gives money to local educational organizations to buy secular learning materials and computer equipment and lend them to schools -- including religious schools. The material itself is not supposed to be religiously oriented, and the allocation of the resources to schools is done in a neutral fashion. At the same time, the aid to the schools is a fairly direct government subsidy of religious educational institutions.

The case presents a genuine problem: To disallow the program would mandate discrimination against schools on the basis of their having religious affiliations. To uphold it would validate public support for religious institutions. The Supreme Court seems likely to approve this program. The important challenge for the court, should it do so, will be to avoid a more sweeping validation of the capacity of religious educational institutions to receive public money.

Establishment Clause principles tend to get stated in bright-line terms, but the reality is that this area of the law is a muddle. The court actually has upheld certain state aid to religious schools, and it's hard to see why these computers are different as a matter of principle. The line-drawing process between what is acceptable, and what is not, is necessarily arbitrary and subjective and seems utterly divorced from the constitutional text itself.

Moreover, the law in question in this case is pretty benign. It seems carefully drawn, in the sense that it offers some safeguards to ensure both that the government funds are not used to acquire religious materials and that the materials acquired are not used to further the religious missions of the parochial schools.

The importance of this case, in other words, is not that the broad separation of church from state depends on whether or not religious schools can receive computer equipment and library books on the same basis as other private schools. Rather, the case is important for the guidance it will offer Congress and the states regarding the standards for acceptable uses of public money with respect to religious schools.

The danger is that the court will enunciate a principle under which public money -- as long as it is provided in a neutral fashion between religious and nonsectarian organizations -- could be used by religious groups for an array of secular purposes. To cite one possibly extreme example: Could the state build entire school buildings for religious schools if it agreed to do so for all private schools?

The proper approach for the court is to rule narrowly. Upholding this program is probably harmless -- but it must be done in a harmless fashion as well.