 One document of interest concerning the question of influence is a letter to Philip Jourdain, dated September 5, 1909. Jourdain had sent Russell the draft of a long survey article on Frege’s work, in which he mentions Jones’s distinction, in Jones (1890) and (1982a), between intension and denotation—a distinction endorsed, as he noted in the published version of the article, by Keynes in the fourth (and final) edition of his influential text, Studies and Exercises in Formal Logic (Jourdain, 1911–12, 201–2, footnote 153). Although Jourdain’s letter is now lost, it appears he is querying Russell about the relation between Jones’s distinction and Frege’s (and, quite possibly, Russell’s related distinction between meaning and denotation). Here Russell responds: