In this paper I discuss how critical realism in economics can help under-labouring for an alternative economic and social theory. The contributions of the Cambridge tradition in economics, which also influenced critical realism in economics, will prove most useful for developing an alternative economic and social theory. I will argue that while an earlier revival of classical political economy in the Cambridge tradition focused on the reproduction of economic structures, critical realism in economics has been concerned with the reproduction of social structures. I will discuss how these projects recover the framework that existed within classical political economy, and was brought to its most advanced stage by Marx. Such a framework focused on the economic reproduction of a surplus, and on its (institutional) distribution through the various social classes under a given social structure. The social ontology of critical realism enables us to understand why the study of reproduction of a (internally related) system is the best starting point for the development of economic and social theory.