At the Diet of Augsburg in 1530 Philip Melanchthon advised against discussion of the priesthood of all believers, relegating it to the “odious and unessential articles which are commonly debated in the schools.” In the Augsburg Confession, which had already been finished and read when he gave this judgment, the doctrine is passed over in silence. But Protestant tradition has not followed Melanchthon in this respect. The priesthood of all believers has come to be regarded, along with Biblical authority and salvation by faith, as one of the three main points of evangelical theology. Like the other two, however, it has not always been interpreted in the same way, nor taken as seriously in practice as in theory. All too often it has become a dead letter in a clergy-dominated institution. And where it has come alive again, it has been used to support a bewildering variety of practices, such as Congregational polity, the Quaker meeting, Pietistic ecclesiolae, and the Methodist commissioning of lay preachers. Sometimes, again, it has become associated with such slogans as “the right of private judgment” or “immediate access to God,” and interpreted so individualistically that any institutional or corporate expression of it becomes unthinkable. Finally, it is perhaps not superfluous to point out that the “royal priesthood” is not a Protestant invention, but a Biblical category, which had an interesting history before Luther and has never been wholly neglected in the “Catholic” tradition. This fact, too, complicates the problems of interpretation.