ABSTRACT This paper explores the notion of proof in clinical psychoanalysis by reconsidering an argument Freud made concerning the relation between successful psychoanalytic treatment and truth, dubbed the “Tally Argument” by the philosopher Adolf Grünbaum. I first reiterate criticisms of Grünbaum’s reconstruction of this argument, which bring out the degree to which he has misunderstood Freud. I then offer my own interpretation of the argument and the reasoning that underlies its key premise. Drawing from this discussion, I explore three forms of proof, each inspired also by analogies with other disciplines. Laurence Perrine’s “The Nature of Proof in the Interpretation of Poetry” stimulates my discussion of inferential proof, the relevant form of which involves proving an interpretation through a strong enough Inference to the Best Explanation. Mathematical proof stimulates my discussion of apodictic proof, of which psychoanalytic insight is a fitting example. Finally, holism in legal reasoning stimulates my discussion of holistic proof, which provides a reliable means by which therapeutic success can verify epistemic conclusions. These three forms of proof can play a crucial role in ascertaining psychoanalytic truth.