Abstract The distinction between thick and thin concepts has been a central part of recent discussion in metaethics. Whilst there is a debate regarding how best to characterise the distinction, it is commonly accepted that ethical theorising traditionally focuses on the thin, leading some to contend that moving from considering thin to thick concepts leads to a very different, and preferable, conception of ethics. Not only does a similar distinction between thick and thin concepts suggest itself within epistemology, traditional discussion within epistemology also seems to focus on the thin in a similar manner. The question of a possible parallel beckons: Is there a comparable distinction between thick and thin epistemic concepts? Would a move from thin to thick lead to an alternative and/or preferable epistemology?