It has usually been assumed by Schiller's biographers that in his intense longing for liberty he was embittered by this disappointment, and that in his mood of wrath he now took up his neglected play and poured into it, hissing hot, the whole fury of his quarrel with the world. There is, however, no evidence that he really hoped to win his release from the academy in the year 1779, or that the thesis just spoken of was regarded as a graduation thesis.[14] Neither his own letters nor those of his friends indicate that he was angry at being kept in school another year. Probably the critics have made too much out of this factor of personal disgruntlement. Schiller was a poetic artist, and his first play is much more than the wild expression of a plucked student's resentment. Nevertheless it is only natural to suppose that his proud and ambitious spirit chafed more or less under the requirements of an academic routine that his manhood had outgrown. That he succeeded after all, at the end of the year 1779, in capturing a number of prizes and received them in the presence of Goethe and the Duke of Weimar, who happened just then to be visiting Stuttgart, could do but little to sweeten the bitter dose that had been prescribed for him. He now set about the preparation of a new thesis, and in the intervals of his professional occupation he worked with feverish energy upon 'The Robbers'. To gain time for writing he would often feign illness, and when the duke or an inspector surprised him would hide his manuscript in a big medical treatise kept at hand for the purpose. A few comrades who were in the secret eagerly watched the progress of his work and vociferously applauded the scenes which he now and then read to them. One of these comrades has left it on record that in the excitement of composition Schiller would often stamp and snort and roar.--And thus it was, in the stolen hours of the night and driven by the demon that possessed him, that he bodied forth his titanic drama of revolt. It was virtually finished during the year 1780. In after-time Schiller reasoned himself into the conviction that art must be 'cheerful',[15] but very little of cheerfulness went to the composition of 'The Robbers'. It was the disburthening of an oppressed soul that suffered horribly at times from morbid melancholy--the chicken-pox of youthful genius. A letter of June, 1780, shows how he had battled with the specters of despair. Writing to Captain von Hoven, whose son had lately died, he says: