On 7 May 1437, in a ritual both sad and absurd, the Council of Basel broke apart in discord and disorder. Two factions in the cathedral session that morning, each “simultaneously reading its decree, shouting its Placet and singing its Te Deum,” divided the house on the issue of selecting a site for unification talks with the Church of Constantinople. The council that claimed the authority to rule Christianity in concordantia catholica (in universal harmony), the council that proclaimed its primacy over the pope, demonstrated its incapacity to put its claims into practice. Nicholas of Cusa, a prominent figure in the conciliarists' camp and author of the 1433 treatise Concordantia catholica, the declaration by which the council intended to reassert its supremacy over the papacy, was on the side of the minority that morning. On this occasion the learned conciliarist found himself in the unusual position of supporting Pope Eugenius IV. What had caused his change of mind, or heart, or, at least, position? Had Cusa indeed changed, or beneath this apparent conversion was he constant in his convictions?