This paper revisits the conception of heterodox economics advanced by Tony Lawson in 2006 and critically assesses its reception. For Lawson, the nature of heterodox economics is a shared commitment to a social ontology of the type that he has defended. This is an assessment that, although influential, has by no means replaced the prevailing view. I argue that an important reason for the lack of uptake has been the mistaken interpretation that Lawson's thesis implies that heterodox economists never use mathematical models. On the contrary, the strength of Lawson's assessment is that it allows for heterodox economists who use mathematical modelling, whilst also identifying why this is, in most cases, inappropriate. This paper argues that Lawson's conception of the nature of heterodox economics is powerful as it is able to coherently capture the current variety of approaches categorised as heterodox, explain why a distinction between the heterodoxy and the mainstream is still justified, whilst also providing a clear avenue towards improving the general explanatory success of contributions made by heterodox economists.