Chapter 21 — Part II: The Sacraments — Holy Orders
Section 20. This power was also possessed by the Jews; but though it was superior in dignity to that with which priests were invested under the law of nature, yet it must be regarded as far inferior to the spiritual power that is found in the New Law. For the latter is heavenly, and surpasses all the power of Angels; it is derived not from the Mosaic priesthood, but from Christ our Lord who was a priest, not according to the order of Aaron, but according to the order of Melchisedech. For He it is who, Himself endowed with the supreme power of granting grace and remitting sins, left to His Church this power, although He limited it in extent and attached it to the Sacraments.