Which came first, the procedure or the substance? Justificational priority and the substance-procedure distinction

Sometimes, we are justified in adopting a certain procedure because it leads to a just outcome. A paradigmatic example is dividing a cake using the 'youcut-I-choose' method: the one who cuts the cake is the last to get her share. This procedure is justified because it tends to lead to the just outcome-an equal division of the cake. However, at times the direction of justification is reversed. Think, for example, of a tennis match in which a coin toss is utilized to determine which player will serve first. In this case, the outcome is justified in virtue of its being a product of that (fair) procedure. We can call these two phenomena 'justificational priority' of the outcome and of the procedure, respectively. This article suggests that the concept of justificational priority can be applied to the legal classification of norms as 'substantive' or 'procedural'. Such classification is required, for instance, in cases of conflict of laws. It is argued that if a certain substantive outcome has justificational priority over a certain norm, which is conceptually (or philosophically) procedural, then this norm should be legally classified as 'substantive'. In contrast, if a certain (conceptually) procedural norm has justificational priority over the substantive outcome, then, in general, it should be legally classified as 'procedural'.