A "GREAT DEBATE" on criminal procedure is currently in process. Judges, prosecutors, the police, defense lawyers, law teachers, practitioners in other fields; and laymen-both informed and uninformed-are taking part. The debate has been so focused that it can result in constructive achievement of the highest order. The American Bar Association has undertaken a large-scale program to promulgate minimum standards in the entire field of criminal justice.' The American Law Institute's Model Code of Pre-Arraignment Procedure has advanced to the stage where it is expected that a tentatve draft, at least of the most vital parts, can be published early in 1966.2 Such model codes for the nation and the fifty states-providing, it is to be hoped, a choice of solutions of certain difficult issues-will strike a fair balance between society's need for protection against crime and the interests of suspected and accused persons, a balance based on thorough investigation of facts and consideration of the views of all parts of the spectrum. Granted that such codes would not be enacted immediately or universally, and ought not to be enacted uniformly, they would nevertheless set workable standards for the police and afford useful guidelines for judges.' They are indeed a splendid prospect, although one that is long overdue. t This article comprises the text of the 1965 Morrison Lecture given to the State Bar of California on September 23, 1965. But for the omission of some introductory remarks and the addition of footnotes, it is printed substantially as delivered. The writer is grateful for aid in the preparation of the lecture by his law clerk at the 1964 Term, Michael Boudin, LL.B. Harvard 1964, and for the editorial assistance of his law clerk at the 1965 Term, Stephen A. Grant, LL.B. Columbia 1965. Needless to say, he is voicing only personal views, previously intimated in his concurrence in Collins v. Beto, 348 F.2d 823, 832 (5th Cir. 1965), and is in no way speaking for the court of which he is a member. The citations make no attempt at full coverage either of the case law or of the vast commentary.