What does laughter mean? What is the basal element in the laughable? What common ground can we find between the grimace of a merry-andrew, a play upon words, an equivocal situation in a burlesque and a scene of high comedy? The essay on Laughter originally appeared in a series of three articles in one of the leading magazines in France, the Revue de Paris. The book has been highly successful in France. It has been translated into Russian, Polish, and Swedish. German and Hungarian translations are under preparation. Its success is due partly to the novelty of the explanation offered of the comic, and partly also to the fact that the author incidentally discusses questions of still greater interest and importance. Thus, one of the best known and most frequently quoted passages of the book is that portion of the last chapter in which the author outlines a general theory of art.