An invisible but enduring legacy of the New Haven School, understood through this paper’s counter-narrative, is a new vista through which to caution against the pitfalls of policy reasoning and to demand its promises. International legal theory has a relatively clear sense about abuse of deduction when found in legal interpretation, but it has little to say about similar defects in policy reasoning. Equally undertheorized are our ideas about the very concept of policy and its place in international legal argumentation. Pursued policy objectives might be principled or flexible and their application flexible or principled. So a combination of principled policies and flexible application of those policies or vice-versa might well permeate the words and practice of international lawyers, used simultaneously or selectively – depending on the context – to address international legal problems. And then there is percolation of these conflicting modalities – principled policies and unprincipled applications or the other way around – through different professional roles that international lawyers habitually adopt. We can begin to understand all that complexity only when we acknowledge the fallacy of an inherent association between law and formalism and between policy and anti-formalism. Re-telling the story of the Yale School is an effort to do just that.