What 'extended me' knows

Arguments for the ‘extended mind’ seem to suggest the possibility of ‘extended knowers’—agents whose specifically epistemic virtues may depend on systems whose boundaries are not those of the brain or the biological organism. Recent discussions of this possibility invoke insights from virtue epistemology, according to which knowledge is the result of the application of some kind of cognitive skill or ability on the part of the agent. In this paper, I argue that there is a fundamental tension in these appeals to cognitive virtue. The tension centers on the presence of a tool or technology as an object of awareness, hence something apt for epistemically virtuous engagement on the part of the agent. I highlight a dilemma: the better something looks as a non-biological element of the machinery of mind, the worse it looks as a potential object of any specifically epistemic skill or ability on the part of the agent. The tension is resolved, I argue, by thinking about sub-personal forms of epistemic hygiene. I examine one such form (rooted in the vision of the ‘predictive brain’), and show how it sits neatly with the vision of the extended mind. I end by asking what we can still reasonably expect, given this more complex sub-personal story, by way of agent-level cognitive hygiene.