For their courteous and generous cooperation the editor is greatly indebted to the authors and publishers of all the plays included. He is equally grateful to other dramatists who were personally as cordial in intention but quite impotent to grant copyright privileges. In addition, he has received most friendly and cordial criticism from friends and friendly strangers to whom he appealed--among others, from Mr. Harold Brighouse; Mr. Theodore Hinckley, editor of "Drama"; Mr. Clarence Stratton, now Director of English at Cleveland, and author of a forthcoming book on the Little Theatre in this country; Mr. Allan Monkhouse, author of "Mary Broome" and "War Plays"; Professor Allan Abbot, of Teachers College, Columbia University; Mr. Frank G. Thompkins, of Central High School, Detroit; Mrs. Mary Austin; Professor Earl B. Pence, of De Pauw University; Professor Brander Matthews; and Mrs. Alice Chapin. Indebtedness to many lists is obvious, particularly to that of the Drama League and the National Council of Teachers of English, and that of Professor Pence in the "Illinois Bulletin." "Ile" is reprinted by special arrangement with the author and with Boni and Liveright, publishers, New York. "Ile" is reprinted from the volume "The Moon of The Caribbees" and six other plays of the sea, which volume is one of the series of plays by Mr. O'Neill, the series including "Beyond the Horizon," a drama in four acts, "The Straw," a play in three acts and five scenes, "Gold," a play in four acts and "Chris" a play in four acts. INTRODUCTION: ON THE READING OF PLAYS The elder Dumas, who wrote many successful plays, as well as the famous romances, said that all he needed for constructing a drama was "four boards, two actors, and a passion." What he meant by passion has been defined by a later French writer, Ferdinand Brunetiere, as a conflict of wills. The Philosopher of Butterbiggens, whom you will meet early in this book, points out that "what you are all the time wanting" is "your own way." When two strong desires conflict and we wonder which is coming out ahead, we say that the situation is dramatic. This clash is clearly defined in any effective play, from the crude melodrama in which the forces are hero and villain with pistols, to such subtle conflicts, based on a man's misunderstanding of even his own motives and purposes, as in Mr. Middleton's "Tides."