23 We recommend equally that all seminarists have in their hands, and frequently peruse, that golden book known as the Catechism of the Council of Trent, or Roman Catechism, dedicated to all priests invested with the pastoral office (Catechismus ad Parochos). Noted both for the abundance and accuracy of its teaching and for elegance of style, this catechism is a precious summary of the whole of theology, dogmatic and moral. The priest who knows it thoroughly has always at his disposal resources which will enable him to preach with fruit, to acquit himself fitly in the important ministry of the confessional and the direction of souls, and be in a position to refute triumphantly the objections of unbelievers.
Source: Depuis le Jour (Vatican.va)