Epistemicism

Epistemicism is the theory of vagueness that holds that vague predicates have perfectly precise boundaries, but these boundaries are unknowable due to the margins of error inherent in human knowledge. The view is most closely associated with the philosopher Timothy Williamson, who argues that there is a precise number of grains that makes a heap and a precise height that makes a person tall — we simply cannot know what these numbers are. The epistemicist preserves classical logic and bivalence at the cost of accepting that there are truths in principle inaccessible to us. The central objection is that this epistemic inaccessibility is not a natural fact about cognition but a metaphysical artifact of treating linguistic indeterminacy as hidden determinacy — a maneuver that supervaluationists reject as confusion of semantics with ignorance.

Epistemicism is the philosophical equivalent of sweeping dust under the rug: the boundary is still there, you just can't see it. But the rug is not the floor.