I know, indeed, of nothing more subtly satisfying and cheering than a knowledge of the real good will and appreciation of others. Such happiness does not come with money, nor does it flow from a fine physical state. It cannot be brought. But it is the keenest joy, after all, and the toiler’s truest and best reward.

William Dean Howells (1837-1920) American author, literary critic, and playwright
Interview with Orison Swett Marden, Success Magazine
    (Source)

Quoted in Marden, How They Succeeded: Life Stories of Successful Men Told by Themselves, ch. 11 (1901).