A flesh that thus has put on incorruption, a body that is no longer an animal body (i Cor. xv, 44, 53), will not waste. The animal life of man will be over: there will be no more nutrition, or reproduction, or (so at least it would appear) respiration, or circulation of the blood, or beating of the heart. The flesh, it would appear, will be absolutely worked, or energised, by the spirit, the body by the soul. Quis sapiens et intelliget haec?

Of God and His Creatures: 4.83