Both leading American realists, both dedicated and militant socialists, Jack London and Upton Sinclair were nevertheless completely different in temperament and philosophy of life. Although they appreciated each other's works, they only met twice, in circumstances not entirely favorable for the development of a friendship. Whereas London hailed the publication of Sinclair's The Jungle with generous praise, thus propelling the book and its author toward international fame, Sinclair was less generous in his appraisal of London, basing his criticism not on the work but on the man. Voicing his own deep-set puritanical nature, he damned London for such sins as smoking, drinking, enjoying sex, resigning from the Socialist party, and making too much money? As Charmian London commented, Sinclair's misapprehensions were partly due to his lack of personal acquaintance with London and to his never having seen him sober, both their meetings having taken place in New York where London was seldom on his best behavior. It is unfortunate that Sinclair did not accept London's invitation to visit him at his Glen Ellen ranch in California, since it would have been his only opportunity to see him at work, sober and in his own surroundings.