Open and closed systems and the Cambridge School

In recent years a group of researchers at Cambridge (UK) have (re)introduced conceptions of open and closed systems into economics. In doing so they have employed these categories in ways that, in my assessment, both facilitate a significant critique of current disciplinary practices and also point to more fruitful ways of proceeding. In an issue of this journal, Andrew Mearman has advanced three criticisms of the Cambridge position which, if valid, would seriously undermine this assessment. Below I defend the Cambridge position against Mearman's criticisms.