This thesis has the twofold purpose of revealing, within its limits, the way in which the streams of rationalism and romanticism flow together in the works of Carlyle and of Shaw, and of indicating that Shaw was not only similar to Carlyle in many of his attitudes, but owed the latter a debt of gratitude for providing the basis, Past and Present, of Major Barbara. Chapter one of the thesis is concerned with outlining, in general terms, why Shaw belongs primarily to the nineteenth century and to romanticism, and I use Carlyle as a yard-stick for comparison. Succeeding chapters are concerned with a direct comparison between Carlyle’s Past and Present and Shaw’s Major Barbara, but will refer the reader constantly to the idea that the central area of common significance in the two authors is the peculiar marrying of romantic outlook to rational argument. In the final chapter, on “Captains of Industry”, apropos the names of one of Carlyle’s, and one of Shaw’s, characters, what seems to me complete proof of Shaw’s indebtedness to Carlyle.