Tacit knowing as a concept and legitimate topic of scholarship came up in philosophical research in the second half of the 20th century in the form of some influential works by Michael Polanyi (although similar concepts had been discussed before). Systematic epistemological studies on the topic are still scarce, however. In this article, I support the thesis that tacit knowing pervades all our common major divisions of knowledge and that it therefore must not be neglected in epistemological research. By this approach I am simultaneously giving a systematic back-up for Polanyi's claim that the tacit component is found in all knowledge.

Standard accounts of analogy in law picture it as reasoning from the past case (source) to a solution in the case at hand (target). This article argues that the normatively constraining invocations of similarity or likeness presupposed by standard accounts do not obtain. It then sketches an alternative account based on Michael Polanyi's idea of polycentricity (not Lon Fuller's) on which the orientation of analogical reasoning is reversed. A past case (here “target”) is picked and framed in certain ways to persuade the interlocutor about the decision independently reached in the present case (here “source”) through the guidance of tacit knowledge (involving anticipation of what is likely to pass muster with the legal community) which normatively constrains the process.

After an esteemed academic career as a chemist, Michael Polanyi switched to the social sciences and made significant contributions to our understanding of the nature and role of knowledge in society. Polanyi's argument concerning knowledge led him to emphasise the vital importance of decentralised mechanisms of adjustment and coordination, including markets. His article ‘Collectivist Planning’ (1940) enters into debates about the possibility (or otherwise) of centrally planning scientific and economic activity. This early article also foreshadows post-war debates within the Mont Pèlerin Socierty (formed in 1947) concerning the economic role of the state and the future of liberalism.