Reply Obj. 1: As Augustine says (QQ. Vet. et Nov. Test. qu. 19 [*Works of an anonymous author], among the supposititious works of St. Augustine): "How could man have an immortal body, which was sustained by food? Since an immortal being needs neither food nor drink." For we have explained (A. 1) that the immortality of the primitive state was based on a supernatural force in the soul, and not on any intrinsic disposition of the body: so that by the action of heat, the body might lose part of its humid qualities; and to prevent the entire consumption of the humor, man was obliged to take food.
Reply Obj. 2: A certain passion and alteration attends nutriment, on the part of the food changed into the substance of the thing nourished. So we cannot thence conclude that man's body was passible, but that the food taken was passible; although this kind of passion conduced to the perfection of the nature.
Reply Obj. 3: If man had not taken food he would have sinned; as he also sinned by taking the forbidden fruit. For he was told at the same time, to abstain from the tree of knowledge of good and evil, and to eat of every other tree of Paradise.
Reply Obj. 4: Some say that in the state of innocence man would not have taken more than necessary food, so that there would have been nothing superfluous; which, however, is unreasonable to suppose, as implying that there would have been no faecal matter. Wherefore there was need for voiding the surplus, yet so disposed by God as to be decorous and suitable to the state. _______________________
FOURTH ARTICLE [I, Q. 97, Art. 4]
Whether in the State of Innocence Man Would Have Acquired Immortality by the Tree of Life?
Objection 1: It would seem that the tree of life could not be the cause of immortality. For nothing can act beyond its own species; as an effect does not exceed its cause. But the tree of life was corruptible, otherwise it could not be taken as food; since food is changed into the substance of the thing nourished. Therefore the tree of life could not give incorruptibility or immortality.
Obj. 2: Further, effects caused by the forces of plants and other natural agencies are natural. If therefore the tree of life caused immortality, this would have been natural immortality.
Obj. 3: Further, this would seem to be reduced to the ancient fable, that the gods, by eating a certain food, became immortal; which the Philosopher ridicules (Metaph. iii, Did. ii, 4).
On the contrary, It is written (Gen. 3:22): "Lest perhaps he put forth his hand, and take of the tree of life, and eat, and live for ever." Further, Augustine says (QQ. Vet. et Nov. Test. qu. 19 [*Work of an anonymous author], among the supposititious works of St. Augustine): "A taste of the tree of life warded off corruption of the body; and even after sin man would have remained immortal, had he been allowed to eat of the tree of life."