Formal models of social processes, the dominant analytic style of the past 40 years in econometric research, have been used relatively little in evaluating social processes. However, input from both moral philosophy and economics is necessary to adequately evaluate the issues of crime and punishment. The traditional modeling approach to criminal justice among economists is to model criminal activity as an enterprise. Thus, if crime is flourishing, it is a function of a high rate of return for criminal activity. A formal model should also take into account the possible interdependencies among the crime rate, the number of criminals and ex-criminals produced, and the characteristics of the 'felon processing technology.' A model of this type could be used to predict crime rates under given sets of justice policies and all economic conditions. The contribution of moral philosophy, or ethical intiution, is the systematic consideration of 'primary social goods' or values to be promoted in formulating criminal justice policy. The apprehension and punishment of criminals has four major objectives: the protection of society against further crimes by the felon, the rehabilitation of the felon, the punishment of the felon, and the deterrence of felonious activity of others. These objectives reflect a concern for liberty, security, and equality. Moral judgments must be exercised on the degree of emphasis upon each objective. For example, implementation of preventive detention policies would increase security at the expense of liberty. Formal economic models will remain useful in the face of major shifts in emphasis upon primary social goals of the justice system by prediction of the effects of such shifts. Ten references and eight notes are provided.