This work analyzes the centrality of law in nineteenth-century historical and institutional economics and is a prehistory to the new institutional economics of the late twentieth century. In the 1830s the 'new science of law' aimed to explain the working rules of human society by using the methodologically individualist terms of economic discourse, stressing determinism and evolutionism. Practitioners stood readier than contemporary institutionalists to admit the possibilities of altruistic values, bounded rationality, and institutional inertia into their research program. Professor Pearson shows that the positive analysis of law tended to push normative discussions up from the level of specific laws to that of society's political organization. The analysis suggests that the professionalization of the social sciences - and the new science's own imprecision - condemned the program to oblivion around 1930. Nonetheless, institutional economics is currently developing greater resemblances to the now-forgotten new science.