In this paper I argue that understanding is an indispensable epistemic procedure when historians use texts as evidence. On my account understanding installs a norm that determines what kind of event or object a texts is evidence of. Historians can debate which norms should govern a body of texts, and if they reach consensus, they can use that body of texts as an empirical constraint over their historical claims. I argue that texts cannot perform this constraining function without understanding – it is thus indispensable. In order to argue for this position I first discuss two existing accounts of textual evidence in analytic philosophy of science by Kosso and Hurst. Both defend a coherentist position. I show that their coherentist position ...