Reply Obj. 1: The spiritual sense of grace does not reach to the body first and principally, but secondarily and instrumentally, as was said above.
Reply Obj. 2: The body of an animal has no relation to a rational soul, as the human body has. Hence there is no parity.
Reply Obj. 3: Although Christ drew the matter of His body from other men, yet all draw from Him the immortal life of their body, according to 1 Cor. 15:22: "And as in Adam all die, so also in Christ all shall be made alive." _______________________
THIRD ARTICLE [III, Q. 8, Art. 3]
Whether Christ Is the Head of All Men?
Objection 1: It would seem that Christ is not the Head of all men.
For the head has no relation except to the members of its body. Now
the unbaptized are nowise members of the Church which is the body of
Christ, as it is written (Eph. 1:23). Therefore Christ is not the
Head of all men.
Obj. 2: Further, the Apostle writes to the Ephesians (5:25, 27): "Christ delivered Himself up for" the Church "that He might present it to Himself a glorious Church, not having spot or wrinkle or any such thing." But there are many of the faithful in whom is found the spot or the wrinkle of sin. Therefore Christ is not the Head of all the faithful.
Obj. 3: Further, the sacraments of the Old Law are compared to Christ as the shadow to the body, as is written (Col. 2:17). But the fathers of the Old Testament in their day served unto these sacraments, according to Heb. 8:5: "Who serve unto the example and shadow of heavenly things." Hence they did not pertain to Christ's body, and therefore Christ is not the Head of all men.
On the contrary, It is written (1 Tim. 4:10): "Who is the Saviour of all men, especially of the faithful," and (1 John 2:2): "He is the propitiation for our sins, and not for ours only, but also for those of the whole world." Now to save men and to be a propitiation for their sins belongs to Christ as Head. Therefore Christ is the Head of all men.
I answer that, This is the difference between the natural body of man and the Church's mystical body, that the members of the natural body are all together, and the members of the mystical are not all together—neither as regards their natural being, since the body of the Church is made up of the men who have been from the beginning of the world until its end—nor as regards their supernatural being, since, of those who are at any one time, some there are who are without grace, yet will afterwards obtain it, and some have it already. We must therefore consider the members of the mystical body not only as they are in act, but as they are in potentiality. Nevertheless, some are in potentiality who will never be reduced to act, and some are reduced at some time to act; and this according to the triple class, of which the first is by faith, the second by the charity of this life, the third by the fruition of the life to come. Hence we must say that if we take the whole time of the world in general, Christ is the Head of all men, but diversely. For, first and principally, He is the Head of such as are united to Him by glory; secondly, of those who are actually united to Him by charity; thirdly, of those who are actually united to Him by faith; fourthly, of those who are united to Him merely in potentiality, which is not yet reduced to act, yet will be reduced to act according to Divine predestination; fifthly, of those who are united to Him in potentiality, which will never be reduced to act; such are those men existing in the world, who are not predestined, who, however, on their departure from this world, wholly cease to be members of Christ, as being no longer in potentiality to be united to Christ.