Legal decision-making emphasizes, in a very self-conscious way, the justificatory significance of reasons. This paper argues that the obligation to provide reasons for choices, which must be articulated and structured around a set of generally shared and publicly comprehensible categories of thought, can serve to make the space of possible choices ‘concept sensitive’ in a very useful way. In particular, concept sensitivity has the effect of restricting certain movements within the choice space so that some of the systematic difficulties in (...) achieving an equilibrium in social choice which arise out of an excess of rational doing are avoided. The resulting equilibrium is path dependent. But because it is dependent on a choice path which ‘makes sense’ (or is ordered by thought precisely because it is concept sensitive), it is not the sort of arbitary path-dependent social choice which originally concerned Kenneth Arrow. This paper illustrates these points with examples from criminal law procedure, contract law and constitutional law. (shrink)