Various theological voices of the past fifty years—from George Lindbeck to Stanley Hauerwas to Rowan Williams to many others—have striven to locate doctrine, as the 'grammar' of a Christian form of life, within the form of life itself, such that grammar is always intimately tied to the way in which Christians present live and have previously lived in their concrete particularity. Both 'grammar' and 'form of life', in their different ways, are meant to help us recognise legitimate, honest, or true Christianity when we see it: do they play by the same rules we do? Do they have patterns of speaking, experience, and action continuous with those we recognise? This paper poses a problem: there is often a tension between 'grammatical' considerations—the conditions or rules for a form of life—and the focus on a form of life as a pre-theoretical whole of knowing, experiencing, and acting. Such tensions are the site of opportunities for doctrinal or ethical development. When such tensions arise, one must either side with grammar over concrete life, or with concrete life over grammar. Whether we choose 'grammar' as determinative or 'form of life' depends on our confidence in isolating one particular aspect of a united whole—the 'grammar' from 'form of life'—for analysis and exploration, before putting it back into the context of the whole. Those who are so confident may be inclined to make grammar determinative of form of life; those who express doubts side with form of life over grammar. Either way, it seems difficult to put the two together in a single vision, such that both help us discern the direction of doctrinal or ethical development.