PurposeIn order to develop transdisciplinary working across the disciplines, clear epistemological foundations are required. The purpose of this paper is to show that sociocybernetics to provides the required unifying metadisciplinary epistemological foundations and transdisciplinary frameworks.Design/methodology/approachThe authors note that second‐order cybernetics provides a metadisciplinary framework for discerning the causes and cures for the schisms within the natural and cognitive sciences. The particular contributions of sociocybernetics are to extend the second‐order understandings to unify the social sciences and, by incorporating extant sociological theory back into the transdisciplinary pursuits of cybernetics and systems theory, to enlighten and enrich those pursuits.FindingsIn order to highlight the power and fruitfulness of these contributions from sociocybernetics, the authors problematise, deconstruct and reconstruct key concepts concerned with human communication. To do this, they take as central the question, “What is a symbol?” and present a sociocybernetic, transdisciplinary solution. In doing so they make clear the epistemological poverty of approaches in cognitive science that are based on the thesis that brains and computers are both “physical‐symbol systems”.Originality/valueThe paper contributes to the metadisciplinary and transdisciplinary aims of cybernetics and, in particular, uses a sociocybernetic analysis to enlighten foundational issues in cognitive science.