The field of industrial relations, to which labour studies and labour education are closely linked both historically and institutionally, is an interdisciplinary field and, as such, has never securely claimed a single theoretical foundation. This article draws attention to a theoretical framework that may be useful as a way of promoting discussion of the theories that support work in this interdisciplinary field. This theoretical framework is referred to as "Vygotskian", after the Soviet psychologist Lev Semenovich Vygotsky (1896-1934). At once a theory of learning, memory and thinking, this framework emphasises social and historical contexts and foregrounds, the mediating role played by language and the use of artefacts created using language, like laws, rules, textbooks, oral and written discourse, contracts, tests, conventional scripts, rituals, accounting systems, and so on. Activity theory acknowledges its roots in Vygotskian, sociocultural theory and extends to incorporate semiotics, reflecting the attention paid to language artefacts. It places a stronger emphasis on contradictions within systems. While activity theory researchers and sociocultural theory researchers continue to be closely allied, the socioculturalists in the United States tend to continue to study educational contexts, using this theoretical framework to study learning and contexts of learning. The activity theorists, who are largely based in countries other than the United States (Scandinavia, Russia, New Zealand, for example), are studying other contexts including the workplace. The activity theorists, who are largely based in countries other than the United States (Scandinavia, Russia, New Zealand, for example), are studying other contexts including the workplace. This article considers the usefulness of activity theory in studying the workplace. It also discusses the four principles of activity theory, as well as the need for a theoretical framework that enables to escape from the unity, contradiction-free view of the workplace.