Pope Paul VI
Sacerdotalis Caelibatus §32
Sacerdotalis Caelibatus: On the Celibacy of the Priest
32 The consecration to Christ under an additional and lofty title like celibacy evidently gives to the priest, even in the practical field, the maximum efficiency and the best disposition of mind, mentally and emotionally, for the continuous exercise of a perfect charity. (55) This charity will permit him to spend himself wholly for the welfare of all, in a fuller and more concrete way. (56) It also obviously guarantees him a greater freedom and flexibility in the pastoral ministry, (57) in his active and living presence in the world, to which Christ has sent him (58) so that he may pay fully to all the children of God the debt due to them. (59)
Source: Sacerdotalis Caelibatus (Vatican.va)