Several observers have noted signs of a growing plurality in mainstream economics. At the same time there has been a growing emphasis in heterodox economics on commonality. The purpose of this paper is to explore the nature of plurality in economics in order to make sense of these characterisations, and to consider the issues raised by this plurality. The critical factor is to distinguish between plurality at the level of theory and evidence, at the level of methodological approach (plurality of methods), and at the meta-methodological level (a plurality of methodologies). First it is argued that, while there is plurality at the level of theory and even of type of evidence in orthodox economics, there continues to be monism in terms of methodological approach, and in attitude to methodological alternatives. In heterodox economics, the commonality of methodological approach does not go far before emerging pluralistically into a variety of approaches. Indeed there is, at the meta-methodological level, a range of arguments in heterodox economics for a plurality of methodologies, that is, a recognition that it is legitimate (if not inevitable) that there is more than one approach to economics.