I.e., in what way will the resurrected bodies of the saints be “impassible”? The following is based on St. Thomas’ opinions of this matter in (ST, Supplement, 82).
Impassibility means immunity from any injury, sickness, or death. The ultimate cause of this is twofold: first, the human soul will be perfectly subject to God and will be free from any sinful desires or mental illness. Second, the human body will be under complete and exhaustive control of the soul. As a result, the soul will want to live and enjoy its reward with great and single-minded desire and, with no aspect of bodily life outside its control, will with perfect effectiveness command the body always to live, never get sick, prosper, act, and exercise its power over the material objects in paradise.
St. Thomas distinguishes between “natural” and “spiritual” alterations of the body. An example of the former is “when the hand is heated by touching a hot object, or becomes fragrant through contact with a fragrant object.” Contrast this with the latter, wherein the eye, in seeing whiteness, does not itself become white. He claims that natural alterations will be impossible for glorified bodies, but spiritual alterations will continue.
Now this is unsatisfactory. Why, for example, can’t there be a fireplace in a “mansion” in paradise, such that both its heat and sight will cause pleasure to some people? It is far better and simpler to argue that the body will be impassible to the full extent the soul wills it to be impassible but also only to that extent. Hence there will be sensation and sensual delight in paradise, whether brought about by natural or spiritual changes. A perfected saint can surely be trusted to allow the reception of useful and happy sensations and to block annoying, damaging, or painful ones as he prefers it.
“Thus it was with the body of Adam,” comments St. Thomas, “which could neither be burned by fire, nor pierced by sword, although he had the sense of such things.” But it remained Adam’s power and choice to distinguish between the pleasures of fire and the pains of fire and to welcome the sensations of the first and easily and competently wave aside and impede the second. It may be, for example, that the heat that one saint will find pleasant will be painful to another saint; yet both will be satisfied by virtue of their sublime self-control to make the body passable or impassible at will.
When thereby willed impassible, the body of a saint will be stronger than any merely material object due to the body’s connection with and empowering influence of the soul. Therefore, no “industrial accident” could over occur in paradise.
Human happiness due to contemplation will differ, asserts St. Thomas, depending on (1) their charity and possibly (2) the strength of their intellect. (I, 12, 6) But people will differ in the quality of their active lives, too. Their power over the body will differ; hence their creative power over the material nature in paradise exercised through their bodies will differ as well. Some people will contemplate better than others in heaven; some will build and act and produce and consume better than others in paradise.
Likewise, things like bodily beauty, gracefulness of motion, keenness of senses, athleticism, manual dexterity, intensity of bodily pleasures, even height (Supplement, 81, 2) will differ depending on one’s merits, as well.
Finally, all senses will be in act in paradise, including even taste, since I see no reason why there cannot be an everlasting improvement in the quality of donuts in the life to come. I will discuss the question of whether Homer Simpson, whose only interest consisted in devouring donuts, would be allowed in the kingdom of God later.