This supreme power is signified by a double metaphor, viz., a __foundation__ and __keys__. First, He says: "Thou art Peter; and on this rock I will build My Church." In order to understand the force of this declaration, it is necessary to call to mind that the name of Peter, which signifies Rock, was not the proper name of the Apostle. His name was Simon. The Lord gave him the name of Peter when He first called him to the apostleship, as an appellation significant of his character and office in the Church. {203} But it was on the occasion of his noble confession of Christ, made by a special inspiration of the Holy Ghost, that He first announced the full import of that mysterious name. St. Peter said, "Thou art Christ"--by this title, which signifies the Anointed One, acknowledging all those divine attributes and prerogatives which are implied in the character of the Messiah of God and Redeemer of the world. The Lord replied in a manner denoting the solemnity of the occasion, and speaking with all the dignity and authority of a Legislator and a Prophet, by conferring on St. Peter, in return for the honor which he had just rendered Him, the highest honor which was in His gift: "Thou art Peter [i.e., a Rock]: and on this Rock I will build My Church." The plain and natural sense of these words of Christ is, that He appoints Peter to occupy a position in the spiritual edifice of the Church corresponding to that occupied by a foundation in a material building. The foundation sustains and, as it were, rules the whole edifice--__i.e.__, by its strength it keeps the whole building in order, and every portion of it in its proper place, thus keeping it from crumbling into ruin--and losing all structural form in a mass of shattered fragments. The foundation is to the building the principle of its unity, repose, order, and durability. {204} Therefore, Peter must be the same to the Church. By him the Church must be sustained, ruled, kept in order, and prevented from falling in pieces, and thus losing its organic form. His authority must be the principle of its unity, strength, and perpetuity. All the force of its laws must be derived from him, and all its authority must ultimately rest on him as its final ground and basis. This is the first portion of our Lord's divine decree concerning St. Peter. Let us now examine the second.