Gerson's chief work was what he did to destroy the great schism. Gregory XI. had died in 1378, one year after Gerson went to the college of Navarre, and since his death the church had had two popes, which to the medieval mind meant two churches and a divided Christ. The schism had practically been brought about by France. The popes had been under French influence so long that it appeared to France a political necessity to have her own pope, and pious Frenchmen felt themselves somewhat responsible for the sins and scandals of the schism. Hence the melancholy piety of Gerson, Pierre d'Ailly and their companions, and the energy with which they strove to bring the schism to an end. During the lifetime of Clement VII. the university of Paris, led by Pierre d'Ailly, Gerson and Nicolas of Clamenges,[1] met in deliberation about the state of Christendom, and resolved that the schism could be ended in three ways,--by cession, if both popes renounced the tiara unconditionally, by arbitration or by a general council. Clement died. The king of France, urged by the university, sent orders that no new pope should be elected. The cardinals first elected, and then opened the letter. In the new elections, however, both at Rome and Avignon, the influence of Paris was so much felt that each of the new popes swore to "cede" if his rival would do so also. Meanwhile in 1395 the national assembly of France and the French clergy adopted the programme of the university--cession or a general council. The movement gathered strength. In 1398 most of the cardinals and most of the crowned heads in Europe had given their adhesion to the plan. During this period Gerson's literary activity was untiring, and the throb of public expectancy, of hope and fear, is revealed in his multitude of pamphlets. At first there were hopes of a settlement by way of cession. These come out in _Protest, super statum ecclesiae_ (ii. 1), _Tract. de modo habendi se tempore schismatis_, _De schismate_, &c. But soon the conduct of the popes made Europe impatient, and the desire for a general council grew strong--see _De concilio generali unius obedientiae_ (ii. 24). The council was resolved upon. It was to meet at Pisa, and Gerson poured forth tract after tract for its guidance. The most important are--_Trilogus in materia schismatis_ (ii. 83), and _De unitate Ecclesiae_ (ii. 113), in which, following Pierre d'Ailly (see Tschackert's _Peter v. Ailli_, p. 153), Gerson demonstrates that the ideal unity of the church, based upon Christ, destroyed by the popes, can only be restored by a general council, supreme and legitimate, though unsummoned by a pope. The council met, deposed both antipopes, and elected Alexander V. Gerson was chosen to address the new pope on the duties of his office. He did so in his _Sermo coram Alexandro Papa in die ascensionis in concilio Pisano_ (ii. 131). All hopes of reformation, however, were quenched by the conduct of the new pope. He