This article argues that the industrial relations (IR) field has had two distinct paradigms — an original paradigm centred on the employment relationship, and a modern paradigm centred on unions and labour–management relations. In practice, IR scholars in the decades after the Second World War frequently adopted the former as a broad principle but followed the latter in research and teaching. The narrower labour–management paradigm has created a significant survival challenge for the IR field, given the marked long-term decline in union density in most countries. I join with others in arguing that to survive and prosper in the years ahead, the field needs to return to an updated version of the original ‘employment relationship’ paradigm. To promote this end, I describe the major features of the original paradigm, including its core positive and normative principle. I also outline how this core principle provides the foundation for an integrative IR theory of the employment relationship, which the field greatly needs to move ahead.