In this talk I examine the philosophical role of illness. I briefly survey the philosophical role accorded to illness in the history of philosophy and explain why illness merits such a role. I suggest that illness modifies, and thus sheds light on, normal experience, revealing its ordinary and therefore overlooked structure. Illness also provides an opportunity for reflection by performing a kind of suspension (epoché) of previously held beliefs, including tacit beliefs. I argue that these characteristics warrant a philosophical role for illness. While the performance of most philosophical procedures is volitional and theoretical, however, illness is uninvited and threatening, throwing the ill person into anxiety and uncertainty. As such it can be viewed as a radical philosophical motivation that can profoundly alter our outlook. I suggest that illness can change the ways in which we philosophise: it may shape philosophical methods and concerns and change one’s sense of salience and conception of philosophy.