Catechesis: Apology XXVII MONASTIC VOWS

Hence it is an intolerable blasphemy when Thomas* says that a monastic profession is equal to Baptism. It is madness to put a human tradition, which has neither a command of God nor a promise, on the same level with an ordinance of Christ which has both a command and a promise of God, which contains a covenant of grace and eternal life.—Ap XXVII:20

*St. Thomas Aquinas in Summa II, 2, q. 189: Hence we read in the Lives of the Fathers (vi, 1) that by entering religion [i.e., taking monastic vows] one receives the same grace as by being baptized.