This project takes up the old question of the nature of truth by seeking to say, at one stroke, both what enables truth and falsity and what lets them matter to us so centrally. Somehow, we as human beings are fundamentally connected to a world in which the truth of statements and the genuineness of things can matter to us deeply and coherently. And yet, I try to show, this coherent unity between being and thinking can also be radically (if not always permanently) broken in the experience of psychosis. I argue that the source of that vulnerable unity must be a contingent event in which I find myself disposed trustingly toward the world, and therein find the world disclosed as trustworthy. Such primitive trust is phenomenally related to trusting a person, and Freudian psychoanalysis shows us that it develops psychologically through relation to a person. As what fundamentally structures self and world, however, this kind of attunement transcends psychology. Our very access to the being of things, i.e., to their compelling importance and organized significance, depends upon it. Thus, I support Martin Heidegger's account of the essence of truth as what first makes accessible the comparisons (between word and thing, for example) on which more traditional theories of truth are based. Yet I also confront Heidegger's phenomenological version of trust by highlighting what is at stake ontologically in our interpersonal psychic development, which psychoanalysis reveals to take place by way of seduction. Heidegger assumes that being must show itself, even if in a concealed way, and thus always takes absence as withdrawal or absencing, rather than as a radical break. By attending to the meaningful phenomena of psychosis, I defend the thesis that our relation to the world is instead opened up and sustained by a fundamental affective attunement (trust) that can dramatically fail. In other words, I try to show that we are exposed to a more radical kind of concealment than Heidegger's thinking of truth seems able to do justice to, a failure of being that can thoroughly overwhelm us.