 Unaware of Ramsey’s result, Bruno de Finetti published (1931) a detailed direct proof that if a subject’s (unconditional) degrees of belief \(\bel(p)\) do not allow such a book, he calls such a subject coherent, then \(\bel\) must satisfy what would later become know as Kolmogorov’s Axioms (1933) for a finitely additive probability function and conversely. In consequence of this fuller explication the forward direction of the Dutch Book argument for belief as probability is commonly attributed to de Finetti alone.