Constitutional law is a problem-solving activity. All problems in constitutional law, without exception, can be analyzed in terms of one or more questions, and all constitutional law questions, without exception, fall into one of two distinct categories: Does the Constitution authorize this governmental action? and does the Constitution prohibit this governmental action? This twofold logic of inquiry into authorization and prohibition guides the constitutional lawyer’s analysis of the problem in a constitutional controversy and provides the intellectual skeleton for constitutional law argument and decision. This chapter will first discuss how the logic of inquiry is used, and then will explain how the two questions are the product of the way the written Constitution is worded and of certain background presuppositions about its purposes.