Chapter Six might well be read as an extended essay with one point in mind; to establish that there is at least one structural principle immanent in the criminal law, the distinction between wrongdoing and attribution. In this chapter our inquiry turns to the inner structure of wrongdoing. We shall attempt to show that wrongdoing consists of two dimensions, one that we shall call the "definition of the offense" and another that we familiarly call "justification." A wrongful act is one that satisfies the definition of the offense and that is unjustified.
We shall approach this substantive distinction by working initially with its procedural precursors. For centuries, lawyers on the Continent spoke of the distinction between the inculpatory case and the exculpatory case; lawyers in the common-law tradition referred, and still refer to the prima facie case and affirmative defenses. This distinction comes to bear in determining a range of procedural burdens: the burden to plead in the indictment, the burden of going forward with the evidence, and, most importantly, the burden of persuasion.