Wittgenstein does not talk much explicitly about reason as a general concept, but this paper aims to sketch some thoughts which might fit his later outlook and which are suggested by his approach to language. The need for some notions in the area of ‘reason’ and ‘rationality’ are rooted in our ability to engage in discursive and persuasive linguistic exchanges. But because such exchanges can (as Wittgenstein emphasises) be so various, we should expect the notions to come in many versions, shaped by history and culture. Awareness of this variety, and of the distinctive elements of our own Western European history, may provide some defence against the temptation of conceptions, such as that of ‘perfect rationality’, which operate in unhelpfully simplified and idealised terms.