Men we deliberate whether to believe some proposition, we feel immediately compelled to look for evidence of its truth. Philosophers have labelled this feature of doxastic deliberation 'transparency'. I argue that resolving the disagreement in the ethics of belief between evidentialists and pragmatists turns on the correct explanation of transparency. My hypothesis is that it reflects a conceptual truth about belief: a belief that p is correct if and only if p. This normative truth entails that only evidence can be a reason for belief. Although evidentialism does not follow directly from the mere psychological truth that we cannot believe for non-evidential reasons, it does follow directly from the normative conceptual truth about belief which explains why we cannot do so.