This interest in mental abnormality has not diminished. O’Neill’s plays are studies in psychopathology. _Beyond the Horizon_ deals with a weak romantic who takes refuge from harsh reality in dreams, and finally dies of consumption. _Gold_ is a melodrama growing out of an insane delusion. _Diff’rent_ is the horrible case-history of a victim of sex-repression. _The Hairy Ape_ describes a character who, if he is not a mere symbol, develops from incipient to raving madness. A play with a normal beginning, “_The First Man_,” turns out to be a study of an emotional fixation. _Welded_ depicts two egotistical introverts in whom goes on the torturing conflict between passionate love and uncontrolled temperament. The flames of lust and greed, fanned into madness--these are the materials of _Desire Under the Elms_. _The Great God Brown_, viewed apart from its symbolism, portrays split personality and madness. _The Fountain_, beneath its exotic romanticism, is the story of an _idée fixe_. The plot of _Strange Interlude_ might have come from the case-book of Freud. If we cannot judge the chief character of _Lazarus Laughed_ by human standards, we can recognise in Caligula and Tiberius realistic studies of psychic abnormalities born of lust, cruelty, and fear. And the author’s latest play, _Dynamo_, is a study of religious mania. The blighting effects of our industrial and social life seem hardly adequate to explain this persistent interest in the pathological. To follow the method of the new psychology which O’Neill uses so largely, we are likely to be correct if we seek an emotional frustration; but American life is hardly the chief cause. Similar interests are seen, for example, in Ibsen, Strindberg, and Wedekind, all of whom must have had their effect on the younger dramatist. My suggestion is that O’Neill has found his highly romantic temperament incompatible with the teachings of science, and has sought to evade the dilemma of modern tragedy by the road of tears, exploiting both pathos and cruelty.