How Practices Matter

I T is uncontroversial that existing institutions and practices 1 are relevant in determining how best to implement a particular principle of political morality, such as a principle of justice.The set of courses of action, regulatory rules, and policies that best realise the demands of justice (whatever one thinks they are) in Geneva will be different from those required in Poland.It is uncontroversial, that is, that information about existing institutional and political contexts is needed in coming to a concrete judgment regarding which particular course of action, regulatory rule, or policy is the best possible way forward from where we are now.Less well understood is whether existing institutions and practices should play any role in justifying, formulating, and grounding 2 the principles themselves, prior, as it were, to their application to the regulatory rules and policies.Imagine, for example, you were to consider what principles of justice, if any, should apply to an international organization (such as the World Trade Organization, or the European Union, or the United Nations), or other political institution (such as the state).How would you proceed in answering that question?Would you assume that the basic principles of justice that are to be applied should be