The argument of this paper is that Enlightenment engagement with diversity is more complex than this account would suggest and that a richer dialogue between the postcolonial and Enlightenment is possible, one in which a conflicted, unresolved encounter can be discerned between leading Enlightenment figures and the testimony they accumulated about diverse cultural practices of non-European peoples. My case in point is John Locke and his engagement with the problem of ‘sati’, a funeral practice among some Hindu communities in which a recently widowed woman would either voluntarily or by use of force and coercion immolate herself on her husband’s funeral pyre. In his early drafts for the Essay concerning Human Understanding (1690) Locke cited sati as part of an argument against innate ideas or principles, but he eliminated it from his examples in the published version. The question is why. I suggest that sati posed a difficulty for Locke because it exposed a conflict in his anthropology, on the one hand confirming an Enlightenment dismay over ‘the power of custom and of opinion based on traditional ways of life’, but on the other hand undermining the principle of self-preservation as absolutely central to natural law on which Locke’s anthropology in the Second Treatise of Government was hinged.