This Article has demonstrated that the failure of commentators and the courts to tackle mens rea analysis head-on has resulted in lasting incoherence in the law. Unintelligible legal doctrine does not simply upset individuals who strive for elegant solutions to legal problems; it also exacts a huge, real-life toll. Juries faced with incoherent legal instructions are likely to become disillusioned about the justice system. Citizens receive inadequate guidance as to acceptable and unacceptable behavior, hampering deterrence -- particularly in the securities-law arena, where one presumably finds mostly rational actors who would be deterred by clear legal rules. Securities regulation is complicated enough, and determining what constitutes a crime in this area is even more difficult. The least that the government should do is provide clear guidance on the crucial issue of criminal mens rea. Fifty years ago, the MPC made clarity possible; it is time now to realize this goal.