Intended as an essay on the perennial topic of the relation between theory and practice, which will not be all theory and no practice, this paper draws on contemporary philosphy of science and clinical theory to catalyze the reader's own further reflections on the topic by suggesting that the meanings of theories and practices are context-dependent, and so the question can never be answered in the abstract, and that the separation of theory and practice is something we can do only in theory, never in practice.