I argue that explanations of doxastic Transparency which go via an appeal to an aim or norm of belief are problematic. In light of this, I offer a new explanation by appeal to a biological function of our mechanisms for belief production. I begin by characterizing the phenomenon, and then move to the teleological and normative accounts of belief, advertised by their proponents as able to give an explanation of it. I argue that, at the very least, both accounts face serious difficulties in this endeavor. These difficulties are a function of seeking to offer an explanation of Transparency at the agential level, either with the subject aiming at truth (as in the teleological account) or being guided by a norm of truth (as in the normative account). I suggest that we should adopt a motivational account of belief, one which severs the connection between belief and truth. After explaining why a motivational account on its own cannot explain Transparency, I suggest supplementing this view with an account of actual world beliefs. My alternative explanation is found at the sub-intentional, non-agential level, secured by biology. This explanation casts Transparency not as related to the nature of deliberation over what to believe, but rather as contingently characterizing the beliefs of some believers, namely those with a particular biological history. My explanation thus parts company with what has come before along two dimensions: it moves away from Transparency being something related to the agent’s aims or commitments, and it understands it as a contingent phenomenon. I close by considering an objection to my view—that Transparency must not be understood as a contingent phenomenon—and considering a nearby alternative position which avoids this consequence. I offer responses to this objection, and reasons not to endorse the nearby alternative. I conclude that my explanation does not face the difficulties of those offered by teleologists and normativists, and, that by moving away from agential explanations, and casting Transparency as contingent, we can provide a successful explanation of it.