The core idea of action research is that there should be an intimate relationship between inquiry and practical or political activities. A challenge to this idea based on an influential ancient Greek hierarchy between theoria and praxis is examined. The contrary, pragmatist, notion that all inquiry arises out of human activity is accepted, but not the instrumentalism sometimes derived from it. Research must be treated as operating on the same plane as any other activity, but the relationship between the two will always be less than isomorphic, and this creates the prospect of severe tensions. These can be managed contextually in two ways: by subordinating inquiry, or by making it primary. Both are legitimate, but any attempt to treat the two components of action research as equal faces contradiction.