The adversary orientation of codes of professional responsibility is accepted as a given, and their justice provisions are interpreted in the most substantive and meaningful way possible. The prosecutor should have a good faith belief in the defendant's guilt. At the trial stage, the prosecutor has additional obligations, but these are limited to assuring that essential premises of the adversary system hold true. This adversarial conception of justice confirms the prosecuting attorney's identity and helps prosecutors understand when codes of professional responsibility oblige them to step out of their role. Consideration is given to the meaning of justice in the context of adversarial trials, prosecuting attorney ethics, achieving justice when adversarial premises fail, problems associated with enforcing a generalized call to justice, and implications of the "do justice" mandate. 275 footnotes