Since the completion of 'Don Carlos' Schiller had written nothing of any moment in the dramatic form. For nine years he had been occupied with historical and philosophic studies which he himself regarded as preparatory to some new and nobler flight of artistic creation. Of course he had been aware all along, none better than he, that great poetry cometh not by theorizing; that theory could have at the best only a general regulative value. At the same time, with the example of Lessing before him, he could not but feel that this regulative value might be very great. And so he had gone resolutely on his way, even after the dread truth had come home to him that he had not long to live and might never be able to reap the fruit of what he was sowing. He had studied certain epochs of history very carefully and had acquired a deeper insight into that tangled interplay of inward motive and outward circumstance which determines the course of events. Philosophy had only deepened his early conviction that man's dignity, his heroism, consists in his free self-determination; but who knew better than he the infinite pathos of the battle between 'will' and 'must'? He had become familiar with the spirit and the technique of the Greek drama and learned to admire its simple and stately architecture. Latterly, however, he had been drawn toward the moderns and had found in the expression of the modern spirit-with all its idealisms, its heights and depths and mysteries of feeling--a higher artistic goal than antiquity had ever imagined. Finally, his association with Goethe had taught him the importance of looking fairly at life and portraying it not indeed just as it is, but in its essential human spirit. This, for him, was to idealize. Two themes had been suggested by his historical studies, and both had haunted his thoughts for years,--'The Knights of Malta' and 'Wallenstein'. The former, if his plan had been carried out, would have yielded a play of the classical type, with few characters and a severely simple structure. In the final balancing of the two subjects 'Wallenstein' prevailed, no doubt because it seemed in advance the easier and the more promising. It pointed to a familiar field where history itself had already shaped in the rough a stupendous and fascinating tragedy. To reproduce the form and pressure of the Thirty Years' War, at one of its most exciting moments, was an alluring problem to a dramatist who had written a history of the struggle, and who had always felt that his strength lay in the historical drama.