This is a conceptual paper giving a fundamental critique of knowledge management, as conceptualised by Nonaka and colleagues by a critical reading of Polanyi, inspired by the Russian psychologist Vygotsky and the US engineering professor Ferguson. The findings are that the externalisation of tacit knowing is much more complex and less prone to be managed than suggested in extant literature. In creating knowledge from such tacit knowing the community pf practice is identified as crucial.