There are a variety of approaches to the limitation of discretion: in loco parentis, constitutional, contract, and trust for fiduciary theories. What has made these principles so far a matter of logical assertion rather than of law is that the courts have chosen not to review a college's use of discretionary authority regarding its students. Only final judgments that appear arbitrary are likely to be overturned by the courts. The application of constitutional limitations to student rights rests generally on the tenability of the public-private distinction. The extent to which private institutions may ignore the standards of the fourteenth amendment is unsure and although decided cases favor the virtually unrestricted freedom of private institutions, private power that requires a waiver of constitutional rights may be unlawful. The courts' new activism in civil liberties cases may forecast more aggressive moves into higher education. There are sound educational reasons for institutions themselves to ensure that justice is not only done but seen to be done. Whatever the legal restraints, colleges should examine the rights and privileges of students for their own sakes. Although most discussion of legal restraints has concerned "power," in understanding or prescribing for the academic institution the important question is one of "authority." If decisions are approached with the understanding that many share in the pattern of authority, then the function of a cautionary statement of legal limits is clear. (JS)