Any satisfactory epistemology must account for the distinction between propositional and doxastic justification. Can infinitism account for it? Proposals to date have been unsatisfactory. This paper advances a new infinitist account of the distinction. The discussion proceeds as follows. Section 1 sets the stage. Section 2 presents Peter Klein's account. Section 3 raises a problem for Klein's account and suggests an improvement. Section 4 raises a further challenge. Sections 5 to 7 consider several unsuccessful attempts to meet the challenge. Section 8 presents my new proposal, which can meet the challenge. Section 9 concludes the discussion.