Reply to Objection 2: Seed is not required for the perfection of the individual, as hair and nails are, but only for the protection of the species.
Reply to Objection 3: Hair and nails are nourished and grow, and so it is clear that they share in some operation, which would not be possible unless they were parts in some way perfected by the soul. And since in man there is but one soul, namely the rational soul, it is clear that they are perfected by the rational soul, although not so far as to share in the operation of sense, as neither do bones, and yet it is certain that these will rise again and that they belong to the integrity of the individual.
Whether the humors will rise again in the body?
Objection 1: It would seem that the humors will not rise again in the body. For it is written ( 1 Cor. 15:50 ): "Flesh and blood cannot possess the kingdom of God." Now blood is the chief humor. Therefore it will not rise again in the blessed, who will possess the kingdom of God, and much less in others.
Objection 2: Further, humors are intended to make up for the waste. Now after the resurrection there will be no waste. Therefore the body will not rise again with humors.
Objection 3: Further, that which is in process of generation in the human body is not yet perfected by the rational soul. Now the humors are still in process of generation because they are potentially flesh and bone. Therefore they are not yet perfected by the rational soul. Now the human body is not directed to the resurrection except in so far as it is perfected by the rational soul. Therefore the humors will not rise again.
On the contrary, Whatever enters into the constitution of the human body will rise again with it. Now this applies to the humors, as appears from the statement of Augustine (De Spir. et Anima xv) that "the body consists of functional members; the functional members of homogeneous parts; and the homogeneous parts of humors." Therefore the humors will rise again in the body.
Further, our resurrection will be conformed to the resurrection of Christ. Now in Christ's resurrection His blood rose again, else the wine would not now be changed into His blood in the Sacrament of the altar. Therefore the blood will rise again in us also, and in like manner the other humors.
I answer that, Whatever belongs to the integrity of human nature in those who take part in the resurrection will rise again, as stated above (AA[1],2). Hence whatever humidity of the body belongs to the integrity of human nature must needs rise again in man. Now there is a threefold humidity in man. There is one which occurs as receding from the perfection of the individual---either because it is on the way to corruption, and is voided by nature, for instance urine, sweat, matter, and so forth---or because it is directed by nature to the preservation of the species in some individual, either by the act of the generative power, as seed, or by the act of the nutritive power, as milk. None of these humidities will rise again, because they do not belong to the perfection of the person rising again.
The second kind of humidity is one that has not yet reached its ultimate perfection, which nature achieves in the individual, yet it is directed thereto by nature: and this is of two kinds. For there is one kind that has a definite form and is contained among the parts of the body, for instance the blood and the other humors which nature has directed to the members that are produced or nourished therefrom: and yet they have certain definite forms like the other parts of the body, and consequently will rise again with the other parts of the body: while another kind of humidity is in transition from form to form, namely from the form of humor to the form of member. Humidities of this kind will not rise again, because after the resurrection each part of the body will be established in its form, so that one will not pass into another. Wherefore this humidity that is actually in transition from one form to another will not rise again. Now this humidity may be considered in a twofold state---either as being at the beginning of its transformation, and thus it is called "ros," namely the humidity that is found in the cavities of the smaller veins---or as in the course of transformation and already beginning to undergo alteration, and thus it is called "cambium": but in neither state will it rise again. The third kind of humidity is that which has already reached its ultimate perfection that nature intends in the body of the individual, and has already undergone transformation and become incorporate with the members. This is called "gluten," and since it belongs to the members it will rise again just as the members will.
Reply to Objection 1: In these words of the Apostle flesh and blood do not denote the substance of flesh and blood but deeds of flesh and blood, which are either deeds of sin or the operations of the animal life. Or we may say with Augustine in his letter to Consentius (Ep. cxlvi) that "flesh and blood here signify the corruption which is now predominant in flesh and blood"; wherefore the Apostle's words continue: "Neither shall corruption possess incorruption."
Reply to Objection 2: Just as the members that serve for generation will be after the resurrection for the integrity of human nature, and not for the operation accomplished now by them, so will the humors be in the body not to make up for waste, but to restore the integrity of human nature and to show forth its natural power.
Reply to Objection 3: Just as the elements are in the course of generation in relation to mixed bodies, because they are their matter, yet not so as to be always in transition when in the mixed body, so too are the humors in relation to the members. And for this reason as the elements in the parts of the universe have definite forms, by reason of which they, like mixed bodies, belong to the perfection of the universe, so too the humors belong to the perfection of the human body, just as the other parts do, although they do not reach its entire perfection, as the other parts do, and although the elements have not perfect forms as mixed bodies have. But as all the parts of the universe receive their perfection from God, not equally, but each one according to its mode, so too the humors are in some way perfected by the rational soul, yet not in the same measure as the more perfect parts.
Whether whatever in the body belonged to the truth of human nature will rise again in it?
Objection 1: It would seem that what was in the body, belonging to the truth of human nature, will not all rise again in it. For food is changed into the truth of human nature. Now sometimes the flesh of the ox or of other animals is taken as food. Therefore if whatever belonged to the truth of human nature will rise again, the flesh of the ox or of other animals will also rise again: which is inadmissible.
Objection 2: Further, Adam's rib belonged to the truth of human nature in him, as ours does in us. But Adam's rib will rise again not in Adam but in Eve, else Eve would not rise again at all since she was made from that rib. Therefore whatever belonged in man to the truth of human nature will not all rise again in him.
Objection 3: Further, it is impossible for the same thing from different men to rise again. Yet it is possible for something in different men to belong to the truth of human nature, for instance if a man were to partake of human flesh which would be changed into his substance. Therefore there will not rise again in man whatever belonged in him to the truth of human nature.
Objection 4: Further, if it be said that not all the flesh partaken of belongs to the truth of human nature and that consequently some of it may possibly rise again in the one man and some in the other---on the contrary: That which is derived from one's parents would especially seem to belong to the truth of human nature. But if one who partook of nothing but human flesh were to beget children that which his child derives from him must needs be of the flesh of other men partaken of by his father, since the seed is from the surplus of food, as the Philosopher proves (De Gen. Animal. i). Therefore what belongs to the truth of human nature in that child belonged also to the truth of human nature in other men of whose flesh his father had partaken.
Objection 5: Further, if it be said that what was changed into seed was not that which belong to the truth of human nature in the flesh of the men eaten, but something not belonging to the truth of human nature---on the contrary: Let us suppose that some one is fed entirely on embryos in which seemingly there is nothing but what belongs to the truth of human nature since whatever is in them is derived from the parents. If then the surplus food be changed into seed, that which belonged to the truth of human nature in the embryos---and after these have received a rational soul, the resurrection applies to them---must needs belong to the truth of human nature in the child begotten of that seed. And thus, since the same cannot rise again in two subjects, it will be impossible for whatever belonged to the truth of human nature in both to rise again in both of them.
On the contrary, Whatever belonged to the truth of human nature was perfected by the rational soul. Now it is through being perfected by the rational soul that the human body is directed to the resurrection. Therefore whatever belonged to the truth of human nature will rise again in each one.
Further, if anything belonging to the truth of human nature in a man be taken from his body, this will not be the perfect body of a man. Now all imperfection of a man will be removed at the resurrection, especially in the elect, to whom it was promised ( Lk. 21:18 ) that not a hair of their head should perish. Therefore whatever belonged to the truth of human nature in a man will rise again in him.
I answer that, "Everything is related to truth in the same way as to being" (Metaph. ii), because a thing is true when it is as it appears to him who actually knows it. For this reason Avicenna (Metaph. ii) says that "the truth of anything is a property of the being immutably attached thereto." Accordingly a thing is said to belong to the truth of human nature, because it belongs properly to the being of human nature, and this is what shares the form of human nature, just as true gold is what has the true form of gold whence gold derives its proper being. In order therefore to see what it is that belongs to the truth of human nature, we must observe that there have been three opinions on the question. For some have maintained that nothing begins anew to belong to the truth of human nature and that whatever belongs to the truth of human nature, all of it belonged to the truth of human nature when this was created; and that this multiplies by itself, so that it is possible for the seed whereof the child is begotten to be detached therefrom by the begetter, and that again the detached part multiplies in the child, so that he reaches perfect quantity by growth, and so on, and that thus was the whole human race multiplied. Wherefore according to this opinion, whatever is produced by nourishment. although it seem to have the appearance of flesh and blood, does not belong to the truth of human nature.
Others held that something new is added to the truth of human nature by the natural transformation of the food into the human body, if we consider the truth of human nature in the species to the preservation of which the act of the generative power is directed: but that if we consider the truth of human nature in the individual, to the preservation and perfection of which the act of the nutritive power is directed, that which is added by food belongs to the truth of the human nature of the individual, not primarily but secondarily. For they assert that the truth of human nature, first and foremost, consists in the radical humor, that namely which is begotten of the seed of which the human race was originally fashioned: and that what is changed from food into true flesh and blood does not belong principally to the truth of human nature in this particular individual, but secondarily: and that nevertheless this can belong principally to the truth of human nature in another individual who is begotten of the seed of the former. For they assert that seed is the surplus from food, either mingled with something belonging principally to the truth of human nature in the begetter, according to some, or without any such admixture, as others maintain. And thus the nutrimental humor in one becomes the radical humor in another.
The third opinion is that something new begins to belong principally to the truth of human nature even in this individual, because distinction in the human body does not require that any signate material part must needs remain throughout the whole lifetime; any signate part one may take is indifferent to this, whereas it remains always as regards what belongs to the species in it, albeit as regards what is material therein it may ebb and flow. And thus the nutrimental humor is not distinct from the radical on the part of its principle (so that it be called radical when begotten of the seed, and nutrimental when produced by the food), but rather on the part of the term, so that it be called radical when it reaches the term of generation by the act of the generative, or even nutritive power, but nutrimental, when it has not yet reached this term, but is still on the way to give nourishment.
These three opinions have been more fully exposed and examined in the Second Book (Sent. ii, D, 30); wherefore there is no need for repetition here, except in so far as the question at issue is concerned. It must accordingly be observed that this question requires different answers according to these opinions.