William Underhill Moore (1879-1949) came to Yale from Columbia in 1929. An expert in commercial bank credit and business organizations, Moore was one of the intellectual leaders of the Legal Realist movement at Yale and a pioneer in the use of social scientific methods in legal research.

Like his Yale contemporary Karl Llewellyn, Moore maintained that judges often applied non-legal norms—especially norms of commercial behavior—in deciding cases. Of the Realists, Moore was the most dedicated to the ideal of scientific objectivity. n a famous 1929 study, “An Institutional Approach to the Law of Commercial Banking,” 38 Yale L. J. 703 (1929), Moore (with Theodore S. Hope, Jr.) attempted to explain and predict banking law decisions that did not appear to derive from existing legal rules by determining the extent to which the facts of the case deviated from normal banking practice. In addition, in a series of articles with Gilbert Sussman, Moore undertook an empirical survey of actual banking practices in discounting notes.

Later scholars have criticized Moore’s empirical studies for their primitive methodology, but his core notion about the importance of empiricism in legal research has largely become conventional wisdom.