An important aspect of the composing process is the element of organization--the coherent development of ideas and considerations of relevance. Most investigations of this aspect have focused on prewriting behavior or on "heuristics,""frames," or other approaches that presuppose that organization is something imposed from the outside and that the composing process begins with the choice of a pattern within which individual sentences are fitted. The fields of critical thinking and applied logic suggest a wholly different perspective: logic, which treats organization, coherence, and relevance as integral features of an exposition or argument. If the logical structure of the composing process is examined, it can be seen that individual topics, theses, or sentences themselves guide the production of what follows (a premise points to a conclusion, a question dictates the sort of answer that will be considered, a claim dictates the supporting evidence to be supplied). These constraints and internal patterns can be discovered in bad reasoning as well as good, and affect both the form and the content of the written product. Failure to recognize these constraints, or general lack of attention to the internal organization governed by applied logic, can lead to a distorted or incomplete model of the composing process. (The paper contains examples from student papers to illustrate the constraints imposed by logic.) (Author/FL)