An interest in Whitman's sources is to be expected, partly because of Whitman's secretiveness. The extent of his indebtedness to Emerson continues to be a problem. That this influence was felt before the first edition of Leaves of Grass in 1855 is questioned, since Walt himself and his earliest biographers say that he had not read Emerson before publishing the first edition of the Leaves. Thus, in his Notes on Walt Whitman, John Burroughs writes: “Up to the time he published the quarto edition [the 1855 edition] he had never read the Essays or Poems of Mr. Emerson at all. This is positively true. In the summer following that publication he first became acquainted with the Essays.” Whitman's friend, W. D. O'Connor, says that Walt had read Kant, Schelling, Fichte, and Hegel, and that any fancied indebtedness to Emerson “is referable to the German source both had drunk from.” Though I believe that Whitman had read more of Emerson before 1855 than he would admit or would allow his friends to admit, I believe, too, that much of the resemblance between the writings of Emerson and Whitman, with reference especially to the first (1855) edition of Leaves of Grass, may be due to their “having drunk from the same source,” that source being Carlyle.