Andy Blunden presents an interdisciplinary review of theories of concepts of interest to cognitive psychology, analytic philosophy, linguistics, and the history of science. Problems within these disciplines establishing reductive theories of the conceptual have led some to abandon concepts altogether in favor of interactionist or narrowly pragmatic approaches.

Blunden responds with an account of the development of the theory of concepts from Descartes through Hegel with special focus on the latter's critical appropriation by early critical social science culminating in the cultural psychology of Lev Vygotsky. He then proposes an approach to concepts which draws on activity theory, according to which concepts are equally subjective and objective: both units of consciousness and of the cultural formation of which one's consciousness is part. This continues the author's earlier work in An Interdisciplinary Theory of Activity (Haymarket, 2011).