In recent years the judgment has emerged that we live in a “post-truth” era and that we increasingly lack the concern for truth. But what would it be to respect the truth? The virtue of truthfulness offers an answer. My dissertation aims to contribute to our understanding of truthfulness by clarifying its constituents and discussing its value. I do so primarily by engaging with Bernard Williams’ analysis in Truth and Truthfulness. According to Williams, truthfulness consists of two virtues of truth: Accuracy and Sincerity. In chapter 1, I investigate Accuracy and, building on Williams’ work, offer an account according to which it involves characteristically ensuring the correctness of one’s beliefs and getting to the truth about the topics one deals with. In chapter 2, I examine Sincerity, which for Williams is a matter of openly communicating one’s beliefs (appropriate given the social context) to deserving others. I highlight the central role that the idea of deserving the truth has in Williams’ understanding, and I argue that Williams does not do enough to show its truth and that, therefore, his account is unsatisfactory for a person striving to live truthfully. In chapter 3, I explore the tensions between the two virtues of truth, a matter Williams largely ignores. I concentrate on the phenomenon of persecution, which jeopardizes one’s ability to live a consistently truthful life. In the final, fourth chapter, I turn to the value of truthfulness. I look at reasons Williams’ work offers for valuing the virtues of truth, analyzing his construction of intrinsic goods and discussing three political arguments for truthfulness (the anti-tyranny argument, argument from political legitimation, argument from liberalism of fear). I critique the former for collapsing the distinction between being and seeming and for ignoring Nietzsche’s relevant discussion of necessary falsehood, and the latter for revealing, despite Williams’ professed political realism, an inadequately realistic view of politics. I suggest that more focused reflection on our flourishing, collective and individual, and its connection to truthfulness is needed. Moreover, I propose that such reflection should pay attention not only to the value of concerning oneself with the truth, but also of suspending that concern—the importance of the latter is shown by psychoanalysis and Donald Winnicott’s work on the intermediate area of play and creative experience. I conclude by discussing the hope for a truthful world that animates Williams’s work, and the prospect of its realization.