Ad fructus uberes (Abundant fruits) was a papal bull issued by Pope Martin IV on 13 December 1281. It affirmed the right of friars to hear confessions and preach without the authorization of secular clergy. The bull was met with fierce opposition from French bishops in particular, who questioned if it contradicted Omnius utriusque sexus (the canon passed by the Fourth Council of the Lateran which mandated yearly confession to a parish priest).
At the same time, Ad fructus uberes itself contained a reminder of Omnius utriusque sexus. This thus triggered a debate between theologians about whether or not Martin had intended for sins already confessed to friars to be reconfessed to parish priests. In his fifth quodlibet delivered just prior to the bull's publication, Henry of Ghent argued that the church did not have the authority to overwrite natural law. He rehashed this argument in response to Ad fructus uberes, and added that yearly confession to a parish priest was still compulsory, even if one chose to confess to a friar. On the other hand, mendicant thinkers such as Richard of Middleton maintained that God could modify preexisting church traditions according to the evolving needs of the laity.
Serious efforts to overturn the bull continued well into the pontificate of Pope Nicholas IV. In December 1286, for instance, a synod of four archbishops and twenty-four bishops convened in Paris to discuss the abrogation of Ad fructus uberes. In 1290, Nicholas endorsed the mendicant-friendly reading of Ad fructus uberes, and forbade further discussion of the bull. Henry of Ghent protested this ruling, and reiterated that the pope lacked the absolute right to grant privileges, especially if they conflicted with divine law. As a result, Henry was suspended temporarily by papal legate Benedict Gaetani (the future Pope Boniface VIII) from teaching at the University of Paris.
Following his assumption of the papacy, Boniface published the bull Super cathedram in 1300, which ruled that mendicant pastoral care required secular authorization. Moreover, Boniface clarified that friars could not preach anything that contradicted the sermons of parish priests, nor could they absolve mortal sins.