“Knowledge” takes a central place in economics. This paper shows that the metaphor pervasively used in neoclassical economics to understand knowledge is that of “capital”. Taking capital as a metaphor of knowledge introduces problems in neoclassical economic theory, as becomes apparent when economics addresses issues of learning and technological development. Instead, it is argued that economists could learn from what philosophers such as Gilbert Ryle and Michael Polanyi have said about how to understand knowledge.
