 Inquiry resistance recurses. For in addition to the unclarity of the borderline case, there is normally unclarity as to where the unclarity begins. Twilight governs times that are borderline between day and night. But we are equally uncertain as to when twilight begins. This suggests there are borderline cases of borderline cases of ‘day’. Consequently, ‘borderline case’ has borderline cases. This higher order vagueness seems to show that ‘vague’ is vague (Hu 2017). We are slow to recognize higher order vagueness because we are under a norm to assert only what we know. When we discuss cases of twilight, we focus on definite cases of this borderline between day and night, not the marginal cases between definite day and definite twilight. 