The disparity of style and quality between O'Neill's early (1920-1932) and later (1932-1940) plays is explored in this study with emphasis upon O'Neill's use of auto symbolic motifs in the later plays, A Touch of the Poet, The Iceman Cometh, and Long Day's Journey Into Night: O'Neill's ability to fuse these auto symbolic motifs into coherent plots creates an emotional intensity in these plays which was absent from his early plays. Beginning with the composition of Ah Wilderness! (1932) O'Neill's plays diverge conspicuously from the earlier compositions, in terms of plot simplicity, character population, reenactment 3f experience in the style of realism, and unity of action and idea. These are the characteristics of his style during the later period which allowed him to make powerful symbols from common objects (autosymbols), such as a uniform and a thoroughbred mare in A Touch of the Poet, a drunkard who despises illusions in The Iceman Cometh, and a wedding dress, a note, and a bank of fog in Long Day's Journey Into Night.Chapter One of this study reviews those characteristics of O'Neill early plays which Eric Bentley has called O'Neill's "notorious faults." According to Bentley and others, O'Neill's early plays are too idea oriented, that is, the themes and symbols of such plays as Mourning Becomes Electra, Strange Interlude, and The Great God Brown do not arise from the action of the story but appear to be grafted onto the story.Chapter One demonstrates that O'Neill's early plays are dramatically ineffective compared to the later ones because of the pretentiousness of his ideas, themes and symbols, and that the incoherent stories and grafted symbolism of the early plays are the result of this pretentiousness.Ronald Peacock's definition of dramatic art is cited in order to demonstrate O'Neill's faulty approach to the drama during the early period and in order to provide a way of talking about the superior quality of the later plays. Before 1932, O'Neill wrote plays in order to demonstrate philosophic ideas; for example, in Dynamo he confronted the idea of the death of the old gods and the failure of science to replace the old gods, but his effort failed because he created an experience (plot) in order to discuss his idea. According to Peacock, this method is backwards; the great play is an experience reenacted as idea, not an idea reenacted as experience. Chapter One suggests that O'Neill's tendency to create a story which demonstrates an idea led him into the grafted symbolism and incoherent plots of the early period, and that this tendency is responsible for the poor characterization of the early plays in which characters such as Nina Leeds, Lavinia Mannon, and Lazarus of Bethany seem too concerned with superpersonal ideas to exist as individuals. After the composition of Ah Wilderness! O'Neill reversed his aesthetic and reenacted experience as ideas.Chapter Two shows how, beginning with his planned cycle, A Tale of Possessors Self-Dispossessed, O'Neill placed a growing emphasis upon simplicity of action and individualized characterization, In A Touch of the Poet, for example, the simplicity of action allows O'Neill to create Con Melody, a vibrant and totally believable character. Although the themes of love-hate relations between family members, excessive pride, and escapism are not new to the O'Neill canon, they now arise from the action and character instead of being grafted onto the work. Furthermore, the principal agent for the transmission of these themes is O'Neill's use of the auto symbolic mare and uniform. Also, the symbolic are not merely associated with an individual, but cluster around each of the major characters of the play. In this way these symbols are auto symbolic because they are both symbol of the idea and simultaneously objects of action-in the plot.These same qualities are characteristic of the symbol of Hickey in The Iceman Cometh. He is both a character in the play and a symbolic figure. In Chapter Three Hickey's dual role associates him symbolically with the lie of the pipe dream and the difficulty and necessity of moral reform. In the play, it becomes obvious that Hickey is a symbol of hopelessness when it is revealed that his reform is also an illusion. Because he is a three-dimensional figure as well as a symbolic figure he is auto symbolic.Chapter Four suggests that Mary's wedding dress, Tyrone's note from Booth, and the fog which encases the Tyrone household are O'Neill's most poignant and emotional auto symbols. O'Neill perfected his symbolic technique in this masterpiece, Long Day's Journey Into Night, in the final scene when Mary carries her wedding dress, which is symbolic of the past and at the same time literally an object of action.In concluding remarks, it is shown that we may account for some of the disparity of style and quality between the early and later plays by an examination of the simplicity of action and unity of symbol and action in A Touch of the Poet, The Iceman Cometh, and Long Day's Journey Into Night, and that the beginning of O'Neill's rejuvenated vision of the drama occurs when he first sketched the cycle, A Tale of Possessors Self-Dispossessed.