Published in 1908, C.S. Peirce’s ‘A Neglected Argument for the Reality of God’ is one of his most difficult articles. Presenting a peculiar entanglement of scientific method and theology, it sketches a ‘humble’ argument for the reality—and not the existence—of God for Musers, that is, those who pursue the activity he calls ‘Musement’. In Musement, Peirce claims, we can achieve a kind of perception of the intertwinement of the three universes of experience: of feeling, of brute fact, and of reason. He also somehow relates each universe to a distinct phase of inquiry, which is described by the use of induction, deduction, and abduction or retroduction. The way that he develops his claims allows him to outline God as an abductive vague hypothesis to explain how those three universes make up a single whole. The hypothesis being vague means that the principle of contradiction does not hold for it. In this presentation, we aim at throwing some light at these points, focusing on the concept of Musement and what is understood as the vagueness of the hypothesis.