Summa - Supplement 1060
1060
We must now consider the impediment of vows and orders. Under this head there are four points of inquiry:
(1) Whether a simple vow is a diriment impediment to matrimony?
(2) Whether a solemn vow is a diriment impediment?
(3) Whether order is an impediment to matrimony?
(4) Whether a man can receive a sacred order after being married?
1061
Objection 1: It would seem that a marriage already contracted ought to be annulled by the obligation of a simple vow. For the stronger tie takes precedence of the weaker. Now a vow is a stronger tie than marriage, since the latter binds man to man, but the former binds man to God. Therefore the obligation of a vow takes precedence of the marriage tie.
Objection 2: Further, God's commandment is no less binding than the commandment of the Church. Now the commandment of the Church is so binding that a marriage is void if contracted in despite thereof; as instanced in the case of those who marry within the degrees of kindred forbidden by the Church. Therefore, since it is a Divine commandment to keep a vow, it would seem that if a person marry in despite of a vow his marriage should be annulled for that reason.
Objection 3: Further, in marriage a man may have carnal intercourse without sin. Yet he who has taken a simple vow of chastity can never have carnal intercourse with his wife without sin. Therefore a simple vow annuls marriage. The minor is proved as follows. It is clear that it is a mortal sin to marry after taking a simple vow of continence, since according to Jerome [*Cf. St. Augustine, De Bono Viduit, ix] "for those who vow virginity it is damnable not only to marry, but even to wish to marry." Now the marriage contract is not contrary to the vow of continence, except by reason of carnal intercourse: and therefore he sins mortally the first time he has intercourse with his wife, and for the same reason every other time, because a sin committed in the first instance cannot be an excuse for a subsequent sin.
Objection 4: Further, husband and wife should be equal in marriage, especially as regards carnal intercourse. But he who has taken a simple vow of continence can never ask for the debt without a sin, for this is clearly against his vow of continence, since he is bound to continence by vow. Therefore neither can he pay the debt without sin.
On the contrary, Pope Clement [*Alexander III] says (cap. Consuluit, De his qui cler. vel vovent.) that a "simple vow is an impediment to the contract of marriage, but does not annul it after it is contracted."
I answer that, A thing ceases to be in one man's power from the fact that it passes into the power of another. Now the promise of a thing does not transfer it into the power of the person to whom it is promised, wherefore a thing does not cease to be in a person's power for the reason that he has promised it. Since then a simple vow contains merely a simple promise of one's body to the effect of keeping continence for God's sake, a man still retains power over his own body after a simple vow, and consequently can surrender it to another, namely his wife; and in this surrender consists the sacrament of matrimony, which is indissoluble. Therefore although a simple vow is an impediment to the contracting of a marriage, since it is a sin to marry after taking a simple vow of continence, yet since the contract is valid, the marriage cannot be annulled on that account.
Reply to Objection 1: A vow is a stronger tie than matrimony, as regards that to which man is tied, and the obligation under which he lies. because by marriage a man is tied to his wife, with the obligation of paying the debt, whereas by a vow a man is tied to God, with the obligation of remaining continent. But as to the manner in which he is tied marriage is a stronger tie than a simple vow, since by marriage a man surrenders himself actually to the power of his wife, but not by a simple vow as explained above: and the possessor is always in the stronger position. In this respect a simple vow binds in the same way as a betrothal; wherefore a betrothal must be annulled on account of a simple vow.
Reply to Objection 2: The contracting of a marriage between blood relations is annulled by the commandment forbidding such marriages, not precisely because it is a commandment of God or of the Church, but because it makes it impossible for the body of a kinswoman to be transferred into the power of her kinsman: whereas the commandment forbidding marriage after a simple vow has not this effect, as already stated. Hence the argument is void for it assigns as a cause that which is not cause.
Reply to Objection 3: If after taking a simple vow a man contract marriage by words of the present, he cannot know his wife without mortal sin, because until the marriage is consummated he is still in a position to fulfill the vow of continence. But after the marriage has been consummated, thenceforth through his fault it is unlawful for him not to pay the debt when his wife asks: wherefore this is not covered by his obligation to his vow, as explained above (ad 1). Nevertheless he should atone for not keeping continence, by his tears of repentance.
Reply to Objection 4: After contracting marriage he is still bound to keep his vow of continence in those matters wherein he is not rendered unable to do so. Hence if his wife die he is bound to continence altogether. And since the marriage tie does not bind him to ask for the debt, he cannot ask for it without sin, although he can pay the debt without sin on being asked, when once he has incurred this obligation through the carnal intercourse that has already occurred. And this holds whether the wife ask expressly or interpretively, as when she is ashamed and her husband feels that she desires him to pay the debt, for then he may pay it without sin. This is especially the case if he fears to endanger her chastity: nor does it matter that they are equal in the marriage act, since everyone may renounce what is his own. Some say, however, that he may both ask and pay lest the marriage become too burdensome to the wife who has always to ask; but if this be looked into aright, it is the same as asking interpretively.
1062
Objection 1: It would seem that not even a solemn vow dissolves a marriage already contracted. For according to a Decretal (cap. Rursus, De his qui cler. vel vovent.) "in God's sight a simple vow is no less binding than a solemn one." Now marriage stands or falls by virtue of the Divine acceptance. Therefore since a simple vow does not dissolve marriage, neither will a solemn vow dissolve it.
Objection 2: Further, a solemn vow does not add the same force to a simple vow as an oath does. Now a simple vow, even though an oath be added thereto, does not dissolve a marriage already contracted. Neither therefore does a solemn vow.
Objection 3: Further, a solemn vow has nothing that a simple vow cannot have. For a simple vow may give rise to scandal since it may be public, even as a solemn vow. Again the Church could and should ordain that a simple vow dissolves a marriage already contracted, so that many sins may be avoided. Therefore for the same reason that a simple vow does not dissolve a marriage already contracted, neither should a solemn vow dissolve it.
On the contrary, He who takes a solemn vow contracts a spiritual marriage with God, which is much more excellent than a material marriage. Now a material marriage already contracted annuls a marriage contracted afterwards. Therefore a solemn vow does also.
Further, the same conclusion may be proved by many authorities quoted in the text (Sent. iv, D, 28).
I answer that, All agree that as a solemn vow is an impediment to the contracting of marriage, so it invalidates the contract. Some assign scandal as the reason. But this is futile, because even a simple vow sometimes leads to scandal since it is at times somewhat public. Moreover the indissolubility of marriage belongs to the truth of life [*Cf. FP, Question [16], Article [4], ad 3; FP, Question [21], Article [2], ad 2; SS, Question [109], Article [3], ad 3], which truth is not to be set aside on account of scandal. Wherefore others say that it is on account of the ordinance of the Church. But this again is insufficient, since in that case the Church might decide the contrary, which is seemingly untrue. Wherefore we must say with others that a solemn vow of its very nature dissolves the marriage contract, inasmuch namely as thereby a man has lost the power over his own body, through surrendering it to God for the purpose of perpetual continence. Wherefore he is unable to surrender it to the power of a wife by contracting marriage. And since the marriage that follows such a vow is void, a vow of this kind is said to annul the marriage contracted.
Reply to Objection 1: A simple vow is said to be no less binding in God's sight than a solemn vow, in matters pertaining to God, for instance the separation from God by mortal sin, because he who breaks a simple vow commits a mortal sin just as one who breaks a solemn vow, although it is more grievous to break a solemn vow, so that the comparison be understood as to the genus and not as to the definite degree of guilt. But as regards marriage, whereby one man is under an obligation to another, there is no need for it to be of equal obligation even in general, since a solemn vow binds to certain things to which a simple vow does not bind.
Reply to Objection 2: An oath is more binding than a vow on the part of the cause of the obligation: but a solemn vow is more binding as to the manner in which it binds, in so far as it is an actual surrender of that which is promised; while an oath does not do this actually. Hence the conclusion does not follow.
Reply to Objection 3: A solemn vow implies the actual surrender of one's body, whereas a simple vow does not, as stated above (Article [1]). Hence the argument does not suffice to prove the conclusion.
1063
Objection 1: It would seem that order is not an impediment to matrimony. For nothing is an impediment to a thing except its contrary. But order is not contrary to matrimony. Therefore it is not an impediment thereto.
Objection 2: Further, orders are the same with us as with the Eastern Church. But they are not an impediment to matrimony in the Eastern Church. Therefore, etc.
Objection 3: Further, matrimony signifies the union of Christ with the Church. Now this is most fittingly signified in those who are Christ's ministers, those namely who are ordained. Therefore order is not an impediment to matrimony.
Objection 4: Further, all the orders are directed to spiritual things. Now order cannot be an impediment to matrimony except by reason of its spirituality. Therefore if order is an impediment to matrimony, every order will be an impediment, and this is untrue.
Objection 5: Further, every ordained person can have ecclesiastical benefices, and can enjoy equally the privilege of clergy. If, therefore, orders are an impediment to marriage, because married persons cannot have an ecclesiastical benefice, nor enjoy the privilege of clergy, as jurists assert (cap. Joannes et seqq., De cler. conjug.), then every order ought to be an impediment. Yet this is false, as shown by the Decretal of Alexander III (De cler. conjug., cap. Si Quis): and consequently it would seem that no order is an impediment to marriage.
On the contrary, the Decretal says (De cler. conjug., cap. Si Quis): "any person whom you shall find to have taken a wife after receiving the subdiaconate or the higher orders, you shall compel to put his wife away." But this would not be so if the marriage were valid.
Further, no person who has vowed continence can contract marriage. Now some orders have a vow of continence connected with them, as appears from the text (Sent. iv, D, 37). Therefore in that case order is an impediment to matrimony.
I answer that, By a certain fittingness the very nature of holy order requires that it should be an impediment to marriage: because those who are in holy orders handle the sacred vessels and the sacraments: wherefore it is becoming that they keep their bodies clean by continence [*Cf. Is 52,11]. But it is owing to the Church's ordinance that it is actually an impediment to marriage. However it is not the same with the Latins as with the Greeks; since with the Greeks it is an impediment to the contracting of marriage, solely by virtue of order; whereas with the Latins it is an impediment by virtue of order, and besides by virtue of the vow of continence which is annexed to the sacred orders; for although this vow is not expressed in words, nevertheless a person is understood to have taken it by the very fact of his being ordained. Hence among the Greeks and other Eastern peoples a sacred order is an impediment to the contracting of matrimony but it does not forbid the use of marriage already contracted: for they can use marriage contracted previously, although they cannot be married again. But in the Western Church it is an impediment both to marriage and to the use of marriage, unless perhaps the husband should receive a sacred order without the knowledge or consent of his wife, because this cannot be prejudicial to her.
Of the distinction between sacred and non-sacred orders now and in the early Church we have spoken above (Question [37], Article [3]).
Reply to Objection 1: Although a sacred order is not contrary to matrimony as a sacrament, it has a certain incompatibility with marriage in respect of the latter's act which is an obstacle to spiritual acts.
Reply to Objection 2: The objection is based on a false statement: since order is everywhere an impediment to the contracting of marriage, although it has not everywhere a vow annexed to it.
Reply to Objection 3: Those who are in sacred orders signify Christ by more sublime actions, as appears from what has been said in the treatise on orders (Question [37], Articles [2],4), than those who are married. Consequently the conclusion does not follow.
Reply to Objection 4: Those who are in minor orders are not forbidden to marry by virtue of their order; for although those orders are entrusted with certain spiritualities, they are not admitted to the immediate handling of sacred things, as those are who are in sacred orders. But according to the laws of the Western Church, the use of marriage is an impediment to the exercise of a non-sacred order, for the sake of maintaining a greater honesty in the offices of the Church. And since the holding of an ecclesiastical benefice binds a man to the exercise of his order, and since for this very reason he enjoys the privilege of clergy, it follows that in the Latin Church this privilege is forfeit to a married cleric.
This suffices for the Reply to the last Objection.
1064
Objection 1: It would seem that a sacred order cannot supervene to matrimony. For the stronger prejudices the weaker. Now a spiritual obligation is stronger than a bodily tie. Therefore if a married man be ordained, this will prejudice the wife, so that she will be unable to demand the debt, since order is a spiritual, and marriage a bodily bond. Hence it would seem that a man cannot receive a sacred order after consummating marriage.
Objection 2: Further, after consummating the marriage, one of the parties cannot vow continence without the other's consent [*Cf. Question [61], Article [1]]. Now a sacred order has a vow of continence annexed to it. Therefore if the husband be ordained without his wife's consent, she will be bound to remain continent against her will, since she cannot marry another man during her husband's lifetime.
Objection 3: Further, a husband may not even for a time devote himself to prayer without his wife's consent (1Co 7,5). But in the Eastern Church those who are in sacred orders are bound to continence for the time when they exercise their office. Therefore neither may they be ordained without their wife's consent, and much less may the Latins.
Objection 4: Further, husband and wife are on a par with one another. Now a Greek priest cannot marry again after his wife's death. Therefore neither can his wife after her husband's death. But she cannot be deprived by her husband's act of the right to marry after his death. Therefore her husband cannot receive orders after marriage.
Objection 5: Further, order is as much opposed to marriage as marriage to order. Now a previous order is an impediment to a subsequent marriage. Therefore, etc.
On the contrary, Religious are bound to continence like those who are in sacred orders. But a man may enter religion after marriage, if his wife die, or if she consent. Therefore he can also receive orders.
Further, a man may become a man's bondsman after marriage. Therefore he can become a bondsman of God by receiving orders.
I answer that, Marriage is not an impediment to the receiving of sacred orders, since if a married man receive sacred orders, even though his wife be unwilling, he receives the character of order: but he lacks the exercise of his order. If, however, his wife consent, or if she be dead, he receives both the order and the exercise.
Reply to Objection 1: The bond of orders dissolves the bond of marriage as regards the payment of the debt, in respect of which it is incompatible with marriage, on the part of the person ordained, since he cannot demand the debt, nor is the wife bound to pay it. But it does not dissolve the bond in respect of the other party, since the husband is bound to pay the debt to the wife if he cannot persuade her to observe continence.
Reply to Objection 2: If the husband receive sacred orders with the knowledge and consent of his wife, she is bound to vow perpetual continence, but she is not bound to enter religion, if she has no fear of her chastity being endangered through her husband having taken a solemn vow: it would have been different, however, if he had taken a simple vow. On the other hand, if he be ordained without her consent, she is not bound in this way, because the result is not prejudicial to her in any way.
Reply to Objection 3: It would seem more probable, although some say the contrary, that even a Greek ought not to receive sacred orders without his wife's consent, since at least at the time of his ministry she would be deprived of the payment of the debt, of which she cannot be deprived according to law if the husband should have been ordained without her consent or knowledge.
Reply to Objection 4: As stated, among the Greeks the wife, by the very fact of consenting to her husband's receiving a sacred order, binds herself never to marry another man, because the signification of marriage would not be safeguarded, and this is especially required in the marriage of a priest. If, however, he be ordained without her consent, seemingly she would not be under that obligation.
Reply to Objection 5: Marriage has for its cause our consent: not so order, which has a sacramental cause appointed by God. Hence matrimony may be impeded by a previous order; so as not to be true marriage: whereas order cannot be impeded by marriage, so as not to be true order, because the power of the sacraments is unchangeable, whereas human acts can be impeded.
1080
We must next consider the impediment of consanguinity. Under this head there are four points of inquiry:
(1) Whether consanguinity is rightly defined by some?
(2) Whether it is fittingly distinguished by degrees and lines?
(3) Whether certain degrees are by natural law an impediment to marriage?
(4) Whether the impediment degrees can be fixed by the ordinance of the Church?
1081
Objection 1: It would seem that consanguinity is unsuitably defined by some as follows: "Consanguinity is the tie contracted between persons descending from the same common ancestor by carnal procreation." For all men descend from the same common ancestor, namely Adam, by carnal procreation. Therefore if the above definition of consanguinity is right, all men would be related by consanguinity: which is false.
Objection 2: Further, a tie is only between things in accord with one another, since a tie unites. Now there is not greater accordance between persons descended from a common ancestor than there is between other men, since they accord in species but differ in number, just as other men do. Therefore consanguinity is not a tie.
Objection 3: Further, carnal procreation, according to the Philosopher (De Gener. Anim. ii, 19), is effected from the surplus food [*Cf. FP, Question [119], Article [2]]. Now this surplus has more in common with that which is eaten, since it agrees with it in substance, than with him who eats. Since then no tie of consanguinity arises between the person born of semen and that which he eats, neither will there be any tie of kindred between him and the person of whom he is born by carnal procreation.
Objection 4: Further, Laban said to Jacob (Gn 29,14): "Thou art my bone and my flesh," on account of the relationship between them. Therefore such a kinship should be called flesh-relationship rather than blood-relationship [consanguinitas].
Objection 5: Further, carnal procreation is common to men and animals. But no tie of consanguinity is contracted among animals from carnal procreation. Therefore neither is there among men.
I answer that, According to the Philosopher (Ethic. iii, 11, 12) "all friendship is based on some kind of fellowship." And since friendship is a knot or union, it follows that the fellowship which is the cause of friendship is called "a tie." Wherefore in respect of any kind of a fellowship certain persons are denominated as though they were tied together: thus we speak of fellow-citizens who are connected by a common political life, of fellow-soldiers who are connected by the common business of soldiering, and in the same way those who are connected by the fellowship of nature are said to be tied by blood [consanguinei]. Hence in the above definition "tie" is included as being the genus of consanguinity; the "persons descending from the same common ancestor," who are thus tied together are the subject of this tie. while "carnal procreation" is mentioned as being its origin.
Reply to Objection 1: An active force is not received into an instrument in the same degree of perfection as it has in the principal agent. And since every moved mover is an instrument, it follows that the power of the first mover in a particular genus when drawn out through many mediate movers fails at length, and reaches something that is moved and not a mover. But the power of a begetter moves not only as to that which belongs to the species, but also as to that which belongs to the individual, by reason of which the child is like the parent even in accidentals and not only in the specific nature. And yet this individual power of the father is not so perfect in the son as it was in the father, and still less so in the grandson, and thus it goes on failing: so that at length it ceases and can go no further. Since then consanguinity results from this power being communicated to many through being conveyed to them from one person by procreation, it destroys itself by little and little, as Isidore says (Etym. ix). Consequently in defining consanguinity we must not take a remote common ancestor but the nearest, whose power still remains in those who are descended from him.
Reply to Objection 2: It is clear from what has been said that blood relations agree not only in the specific nature but also in that power peculiar to the individual which is conveyed from one to many: the result being that sometimes the child is not only like his father, but also his grandfather or his remote ancestors (De Gener. Anim. iv, 3).
Reply to Objection 3: Likeness depends more on form whereby a thing is actually, than on matter whereby a thing is potentially: for instance, charcoal has more in common with fire than with the tree from which the wood was cut. In like manner food already transformed by the nutritive power into the substance of the person fed has more in common with the subject nourished than with that from which the nourishment was taken. The argument however would hold according to the opinion of those who asserted that the whole nature of a thing is from its matter and that all forms are accidents: which is false.
Reply to Objection 4: It is the blood that is proximately changed into the semen, as proved in De Gener. Anim. i, 18. Hence the tie contracted by carnal procreation is more fittingly called blood-relationship than flesh-relationship. That sometimes one relation is called the flesh of another, is because the blood which is transformed into the man's seed or into the menstrual fluid is potentially flesh and bone.
Reply to Objection 5: Some say that the reason why the tie of consanguinity is contracted among men through carnal procreation, and not among other animals, is because whatever belongs to the truth of human nature in all men was in our first parent: which does not apply to other animals. But according to this, matrimonial consanguinity would never come to an end. However the above theory was disproved in the Second Book (Sent. ii, D, 30: FP, Question [119], Article [1]). Wherefore we must reply that the reason for this is that animals are not united together in the union of friendship through the begetting of many from one proximate parent, as is the case with men, as stated above.
1082
Objection 1: It would seem that consanguinity is unfittingly distinguished by degrees and lines. For a line of consanguinity is described as "the ordered series of persons related by blood, and descending from a common ancestor in various degrees." Now consanguinity is nothing else but a series of such persons. Therefore a line of consanguinity is the same as consanguinity. Now a thing ought not to be distinguished by itself. Therefore consanguinity is not fittingly distinguished into lines.
Objection 2: Further, that by which a common thing is divided should not be placed in the definition of that common thing. Now descent is placed in the above definition of consanguinity. Therefore consanguinity cannot be divided into ascending, descending and collateral lines.
Objection 3: Further, a line is defined as being between two points. But two points make but one degree. Therefore one line has but one degree, and for this reason it would seem that consanguinity should not be divided into lines and degrees.
Objection 4: Further, a degree is defined as "the relation between distant persons, whereby is known the distance between them." Now since consanguinity is a kind of propinquity, distance between persons is opposed to consanguinity rather than a part thereof.
Objection 5: Further, if consanguinity is distinguished and known by its degrees, those who are in the same degree ought to be equally related. But this is false since a man's great-uncle and great-nephew are in the same degree, and yet they are not equally related according to a Decretal (cap. Porro; cap. Parenteloe, 35, qu. v). Therefore consanguinity is not rightly divided into degrees.
Objection 6: Further, in ordinary things a different degree results from the addition of one thing to another, even as every additional unity makes a different species of number. Yet the addition of one person to another does not always make a different degree of consanguinity, since father and uncle are in the same degree of consanguinity, for they are side by side. Therefore consanguinity is not rightly divided into degrees.
Objection 7: Further, if two persons be akin to one another there is always the same measure of kinship between them, since the distance from one extreme to the other is the same either way. Yet the degrees of consanguinity are not always the same on either side, since sometimes one relative is in the third and the other in the fourth degree. Therefore the measure of consanguinity cannot be sufficiently known by its degrees.
I answer that, Consanguinity as stated (Article [1]) is a certain propinquity based on the natural communication by the act of procreation whereby nature is propagated. Wherefore according to the Philosopher (Ethic. viii, 12) this communication is threefold. one corresponds to the relationship between cause and effect, and this is the consanguinity of father to son, wherefore he says that "parents love their children as being a part of themselves." Another corresponds to the relation of effect to cause, and this is the consanguinity of son to father, wherefore he says that "children love their parents as being themselves something which owes its existence to them." The third corresponds to the mutual relation between things that come from the same cause, as brothers, "who are born of the same parents," as he again says (Ethic. viii, 12). And since the movement of a point makes a line, and since a father by procreation may be said to descend to his son, hence it is that corresponding to these three relationships there are three lines of consanguinity, namely the "descending" line corresponding to the first relationship, the "ascending" line corresponding to the second, and the "collateral" line corresponding to the third. Since however the movement of propagation does not rest in one term but continues beyond, the result is that one can point to the father's father and to the son's son, and so on, and according to the various steps we take we find various degrees in one line. And seeing that the degrees of a thing are parts of that thing, there cannot be degrees of propinquity where there is no propinquity. Consequently identity and too great a distance do away with degrees of consanguinity; since no man is kin to himself any more than he is like himself: for which reason there is no degree of consanguinity where there is but one person, but only when one person is compared to another.
Nevertheless there are different ways of counting the degrees in various lines. For the degree of consanguinity in the ascending and descending line is contracted from the fact that one of the parties whose consanguinity is in question, is descended from the other. Wherefore according to the canonical as well as the legal reckoning, the person who occupies the first place, whether in the ascending or in the descending line, is distant from a certain one, say Peter, in the first degree---for instance father and son; while the one who occupies the second place in either direction is distant in the second degree, for instance grandfather, grandson and so on. But the consanguinity that exists between persons who are in collateral lines is contracted not through one being descended from the other, but through both being descended from one: wherefore the degrees of consanguinity in this line must be reckoned in relation to the one principle whence it arises. Here, however, the canonical and legal reckonings differ: for the legal reckoning takes into account the descent from the common stock on both sides, whereas the canonical reckoning takes into account only one, that namely on which the greater number of degrees are found. Hence according to the legal reckoning brother and sister, or two brothers, are related in the second degree, because each is separated from the common stock by one degree; and in like manner the children of two brothers are distant from one another in the fourth degree. But according to the canonical reckoning, two brothers are related in the first degree, since neither is distant more than one degree from the common stock: but the children of one brother are distant in the second degree from the other brother, because they are at that distance from the common stock. Hence, according to the canonical reckoning, by whatever degree a person is distant from some higher degree, by so much and never by less is he distant from each person descending from that degree, because "the cause of a thing being so is yet more so." Wherefore although the other descendants from the common stock be related to some person on account of his being descended from the common stock, these descendants of the other branch cannot be more nearly related to him than he is to the common stock. Sometimes, however, a person is more distantly related to a descendant from the common stock, than he himself is to the common stock, because this other person may be more distantly related to the common stock than he is: and consanguinity must be reckoned according to the more distant degree.
Reply to Objection 1: This objection is based on a false premise: for consanguinity is not the series but a mutual relationship existing between certain persons, the series of whom forms a line of consanguinity.
Reply to Objection 2: Descent taken in a general sense attaches to every line of consanguinity, because carnal procreation whence the tie of consanguinity arises is a kind of descent: but it is a particular kind of descent, namely from the person whose consanguinity is in question, that makes the descending line.
Reply to Objection 3: A line may be taken in two ways. Sometimes it is taken properly for the dimension itself that is the first species of continuous quantity: and thus a straight line contains actually but two points which terminate it, but infinite points potentially, any one of which being actually designated, the line is divided, and becomes two lines. But sometimes a line designates things which are arranged in a line, and thus we have line and figure in numbers, in so far as unity added to unity involves number. Thus every unity added makes a degree in a particular line: and it is the same with the line of consanguinity: wherefore one line contains several degrees.
Reply to Objection 4: Even as there cannot be likeness without a difference, so there is no propinquity without distance. Hence not every distance is opposed to consanguinity, but such as excludes the propinquity of blood-relationship.
Reply to Objection 5: Even as whiteness is said to be greater in two ways, in one way through intensity of the quality itself, in another way through the quantity of the surface, so consanguinity is said to be greater or lesser in two ways. First, intensively by reason of the very nature of consanguinity: secondly, extensively as it were, and thus the degree of consanguinity is measured by the persons between whom there is the propagation of a common blood, and in this way the degrees of consanguinity are distinguished. Wherefore it happens that of two persons related to one person in the same degree of consanguinity, one is more akin to him than the other, if we consider the quantity of consanguinity in the first way: thus a man's father and brother are related to him in the first degree of consanguinity, because in neither case does any person come in between; and yet from the point of view of intensity a man's father is more closely related to him than his brother, since his brother is related to him only because he is of the same father. Hence the nearer a person is to the common ancestor from whom the consanguinity descends, the greater is his consanguinity although he be not in a nearer degree. In this way a man's great-uncle is more closely related to him than his great-nephew, although they are in the same degree.
Reply to Objection 6: Although a man's father and uncle are in the same degree in respect of the root of consanguinity, since both are separated by one degree from the grandfather, nevertheless in respect of the person whose consanguinity is in question, they are not in the same degree, since the father is in the first degree, whereas the uncle cannot be nearer than the second degree, wherein the grandfather stands.
Reply to Objection 7: Two persons are always related in the same degree to one another, although they are not always distant in the same number of degrees from the common ancestor, as explained above.
Summa - Supplement 1060