Although John Stuart Mill places considerable emphasis on three information signalling devices – debate, votes and prices – he remains curiously sceptical about the prospects of institutional or social epistemology. In this paper, I explore Mill's modest scepticism about institutional epistemology and compare and contrast that with the attitudes of liberal theorists such as F. A. Hayek and John Dewey who are much more enthusiastic about the prospects of social epistemology as part of their defences of liberalism. The paper examines the extent to which Hayek and Dewey ignore concerns originally raised by Mill. I conclude that Mill's modest scepticism is reflected in the epistemological abstinence of contemporary liberal philosophers such as John Rawls, and that his elevation of philosophy over democracy remains a challenge to contemporary defenders of the political value of social or institutional epistemology.