XIX. To those who say that the enjoyment of the good things we look for will again consist in meat and drink, because it is written that by these means man at first lived in Paradise .
1 But some one perhaps will say that man will not be returning to the same form of life, if as it seems, we formerly existed by eating, and shall hereafter be free from that function. I, however, when I hear the Holy Scripture, do not understand only bodily meat, or the pleasure of the flesh; but I recognize another kind of food also, having a certain analogy to that of the body, the enjoyment of which extends to the soul alone: “Eat of my bread,” is the bidding of Wisdom to the hungry; and the Lord declares those blessed who hunger for such food as this, and says, “If any man thirst, let him come unto Me, and drink”: and “drink ye joy,” is the great Isaiah's charge to those who are able to hear his sublimity. There is a prophetic threatening also against those worthy of vengeance, that they shall be punished with famine; but the “famine” is not a lack of bread and water, but a failure of the word:— “not a famine of bread, nor a thirst for water, but a famine of hearing the word of the Lord.”
2. We ought, then, to conceive that the fruit in Eden was something worthy of God's planting (and Eden is interpreted to mean “delight”), and not to doubt that man was hereby nourished: nor should we at all conceive, concerning the mode of life in Paradise, this transitory and perishable nutriment: “of every tree of the garden,” He says, “you may freely eat.”
3. Who will give to him that has a healthful hunger that tree that is in Paradise, which includes all good, which is named “every tree,” in which this passage bestows on man the right to share? For in the universal and transcendent saying every form of good is in harmony with itself, and the whole is one. And who will keep me back from that tasting of the tree which is of mixed and doubtful kind? For surely it is clear to all who are at all keen-sighted what that “every” tree is whose fruit is life, and what again that mixed tree is whose end is death: for He Who presents ungrudgingly the enjoyment of “every” tree, surely by some reason and forethought keeps man from participation in those which are of doubtful kind.
4. It seems to me that I may take the great David and the wise Solomon as my instructors in the interpretation of this text: for both understand the grace of the permitted delight to be one—that very actual Good, which in truth is “every” good—David, when he says, “Delight thou in the Lord,” and Solomon, when he names Wisdom herself (which is the Lord) “a tree of life.”
5. Thus the “every” tree of which the passage gives food to him who was made in the likeness of God, is the same with the tree of life; and there is opposed to this tree another tree, the food given by which is the knowledge of good and evil:— not that it bears in turn as fruit each of these things of opposite significance, but that it produces a fruit blended and mixed with opposite qualities, the eating of which the Prince of Life forbids, and the serpent counsels, that he may prepare an entrance for death: and he obtained credence for his counsel, covering over the fruit with a fair appearance and the show of pleasure, that it might be pleasant to the eyes and stimulate the desire to taste.
Source: On the Making of Man (New Advent)