 There is an irony in this episode. The last page of the paper, “Is Ethics a Branch of Empirical Psychology?” is marked with a query in Russell’s hand “Shall we spell {Good/good} with”, to which Moore replies “Good = good”—which looks like a succinct formulation of his famous no-definition definition of “good” (“If I am asked ‘How is good to be defined?’ my answer is that it cannot be defined and that is all I have to say about it.” PE: 58). If I am right, Russell’s desire-to-desire theory posed a problem for Moore which it took him five years to solve. But, given the annotation, it seems that the debate on Russell’s paper began a process of conversion that led Russell himself to accept the doctrines of Moore’s Principia Ethica.