In Section II, we explored recent substantive developments in the political economy of science, especially regarding its progressive commercialisation. In doing so, we illustrated the insights available concerning our current predicament from a cultural political economy perspective, employing a relational Marxism. It remains, however, for this perspective to be justified in theoretical terms, regardless of the substantive lessons we have already seen it to be capable of yielding. This theoretical argument will occupy us for the remainder of the book, setting out the steps from the mainstream economics of science to a cultural political economy of research and innovation (R&I), while in the process highlighting the theoretical insights from the (inchoate and ongoing) synthesis and concerted engagement of political economy and science and technology studies (STS).