 In the latter book he advocated a common-sense approach to parenting and the rejection of psychological theories, especially Freudian psychology.His portrait was painted in the winter of 1914–15 by the Swiss-born American artist Adolfo Müller-Ury (1862–1947), but is presently unlocated.Another portrait, by Marie Rosenthal-Hatschek (1871–1942), hangs in the Oskar Diethelm Library at Weill Cornell Medical College.