Summa Th. III EN Qu.65 a.2
Objection: 1. It seems that the order of the sacraments as given above is unbecoming. For according to the Apostle (1Co 15,46), "that was . . . first . . . which is natural, afterwards that which is spiritual." But man is begotten through Matrimony by a first and natural generation; while in Baptism he is regenerated as by a second and spiritual generation. Therefore Matrimony should precede Baptism.
2. Further, through the sacrament of order man receives the power of agent in sacramental actions. But the agent precedes his action. Therefore order should precede Baptism and the other sacraments.
3. Further, the Eucharist is a spiritual food; while Confirmation is compared to growth. But food causes, and consequently precedes, growth. Therefore the Eucharist precedes Confirmation.
4. Further, Penance prepares man for the Eucharist. But a disposition precedes perfection. Therefore Penance should precede the Eucharist.
5. Further, that which is nearer the last end comes after other things. But, of all the sacraments, Extreme Unction is nearest to the last end which is Happiness. Therefore it should be placed last among the sacraments.
On the contrary The order of the sacraments, as given above, is commonly adopted by all.
I answer that The reason of the order among the sacraments appears from what has been said above (Article [1]). For just as unity precedes multitude, so those sacraments which are intended for the perfection of the individual, naturally precede those which are intended for the perfection of the multitude; and consequently the last place among the sacraments is given to order and Matrimony, which are intended for the perfection of the multitude: while Matrimony is placed after order, because it has less participation in the nature of the spiritual life, to which the sacraments are ordained. Moreover, among things ordained to the perfection of the individual, those naturally come first which are ordained directly to the perfection of the spiritual life, and afterwards, those which are ordained thereto indirectly, viz. by removing some supervening accidental cause of harm; such are Penance and Extreme Unction: while, of these, Extreme Unction is naturally placed last, for it preserves the healing which was begun by Penance.Of the remaining three, it is clear that Baptism which is a spiritual regeneration, comes first; then Confirmation, which is ordained to the formal perfection of power; and after these the Eucharist which is ordained to final perfection.
Reply to Objection: 1. Matrimony as ordained to natural life is a function of nature. But in so far as it has something spiritual it is a sacrament. And because it has the least amount of spirituality it is placed last.
2. For a thing to be an agent it must first of all be perfect in itself. Wherefore those sacraments by which a man is perfected in himself, are placed before the sacrament of order, in which a man is made a perfecter of others.
3. Nourishment both precedes growth, as its cause; and follows it, as maintaining the perfection of size and power in man. Consequently, the Eucharist can be placed before Confirmation, as Dionysius places it (Eccl. Hier. iii, iv), and can be placed after it, as the Master does (iv, 2,8).
4. This argument would hold if Penance were required of necessity as a preparation to the Eucharist. But this is not true: for if anyone be without mortal sin, he does not need Penance in order to receive the Eucharist. Thus it is clear that Penance is an accidental preparation to the Eucharist, that is to say, sin being supposed. Wherefore it is written in the last chapter of the second Book of Paralipomenon (cf. 2Ch 33,18): "Thou, O Lord of the righteous, didst not impose penance on righteous men." [*The words quoted are from the apocryphal Prayer of Manasses, which, before the Council of Trent, was to be found inserted in some Latin copies of the Bible.]
5. Extreme Unction, for this very reason, is given the last place among those sacraments which are ordained to the perfection of the individual.
Objection: 1. It seems that the Eucharist is not the principal of the sacraments. For the common good is of more account than the good of the individual (1 Ethic. ii). But Matrimony is ordained to the common good of the human race by means of generation: whereas the sacrament of the Eucharist is ordained to the private good of the recipient. Therefore it is not the greatest of the sacraments.
2. Further, those sacraments, seemingly, are greater, which are conferred by a greater minister. But the sacraments of Confirmation and order are conferred by a bishop only, who is a greater minister than a mere minister such as a priest, by whom the sacraments of the Eucharist is conferred. Therefore those sacraments are greater.
3. Further, those sacraments are greater that have the greater power. But some of the sacraments imprint a character, viz. Baptism, Confirmation and order; whereas the Eucharist does not. Therefore those sacraments are greater.
4. Further, that seems to be greater, on which others depend without its depending on them. But the Eucharist depends on Baptism: since no one can receive the Eucharist except he has been baptized. Therefore Baptism is greater than the Eucharist.
On the contrary Dionysius says (Eccl. Hier. iii) that "No one receives hierarchical perfection save by the most God-like Eucharist." Therefore this sacrament is greater than all the others and perfects them.
I answer that Absolutely speaking, the sacrament of the Eucharist is the greatest of all the sacraments: and this may be shown in three ways.First of all because it contains Christ Himself substantially: whereas the other sacraments contain a certain instrumental power which is a share of Christ's power, as we have shown above (Question [62], Article [4], ad 3, Article [5]). Now that which is essentially such is always of more account than that which is such by participation.Secondly, this is made clear by considering the relation of the sacraments to one another. For all the other sacraments seem to be ordained to this one as to their end. For it is manifest that the sacrament of order is ordained to the consecration of the Eucharist: and the sacrament of Baptism to the reception of the Eucharist: while a man is perfected by Confirmation, so as not to fear to abstain from this sacrament. By Penance and Extreme Unction man is prepared to receive the Body of Christ worthily. And Matrimony at least in its signification, touches this sacrament; in so far as it signifies the union of Christ with the Church, of which union the Eucharist is a figure: hence the Apostle says (Ep 5,32): "This is a great sacrament: but I speak in Christ and in the Church."Thirdly, this is made clear by considering the rites of the sacraments. For nearly all the sacraments terminate in the Eucharist, as Dionysius says (Eccl. Hier. iii): thus those who have been ordained receive Holy Communion, as also do those who have been baptized, if they be adults.The remaining sacraments may be compared to one another in several ways. For on the ground of necessity, Baptism is the greatest of the sacraments; while from the point of view of perfection, order comes first; while Confirmation holds a middle place. The sacraments of Penance and Extreme Unction are on a degree inferior to those mentioned above; because, as stated above (Article [2]), they are ordained to the Christian life, not directly, but accidentally, as it were, that is to say, as remedies against supervening defects. And among these, Extreme Unction is compared to Penance, as Confirmation to Baptism; in such a way, that Penance is more necessary, whereas Extreme Unction is more perfect.
Reply to Objection: 1. Matrimony is ordained to the common good as regards the body. But the common spiritual good of the whole Church is contained substantially in the sacrament itself of the Eucharist.
2. By order and Confirmation the faithful of Christ are deputed to certain special duties; and this can be done by the prince alone. Consequently the conferring of these sacraments belongs exclusively to a bishop, who is, as it were, a prince in the Church. But a man is not deputed to any duty by the sacrament of the Eucharist, rather is this sacrament the end of all duties, as stated above.
3. The sacramental character, as stated above (Question [63], Article [3]), is a kind of participation in Christ's priesthood. Wherefore the sacrament that unites man to Christ Himself, is greater than a sacrament that imprints Christ's character.
4. This argument proceeds on the ground of necessity. For thus Baptism, being of the greatest necessity, is the greatest of the sacraments, just as order and Confirmation have a certain excellence considered in their administration; and Matrimony by reason of its signification. For there is no reason why a thing should not be greater from a certain point of view which is not greater absolutely speaking.
Objection: 1. It seems that all the sacraments are necessary for salvation. For what is not necessary seems to be superfluous. But no sacrament is superfluous, because "God does nothing without a purpose" (De Coelo et Mundo i). Therefore all the sacraments are necessary for salvation.
2. Further, just as it is said of Baptism (Jn 3,5): "Unless a man be born again of water and the Holy Ghost, he cannot enter in to the kingdom of God," so of the Eucharist is it said (Jn 6,54): "Except you eat of the flesh of the Son of Man, and drink of His blood, you shall not have life in you." Therefore, just as Baptism is a necessary sacrament, so is the Eucharist.
3. Further, a man can be saved without the sacrament of Baptism, provided that some unavoidable obstacle, and not his contempt for religion, debar him from the sacrament, as we shall state further on (Question [68], Article [2]). But contempt of religion in any sacrament is a hindrance to salvation. Therefore, in like manner, all the sacraments are necessary for salvation.
On the contrary Children are saved by Baptism alone without the other sacraments.
I answer that Necessity of end, of which we speak now, is twofold. First, a thing may be necessary so that without it the end cannot be attained; thus food is necessary for human life. And this is simple necessity of end. Secondly, a thing is said to be necessary, if, without it, the end cannot be attained so becomingly: thus a horse is necessary for a journey. But this is not simple necessity of end.In the first way, three sacraments are necessary for salvation. Two of them are necessary to the individual; Baptism, simply and absolutely; Penance, in the case of mortal sin committed after Baptism; while the sacrament of order is necessary to the Church, since "where there is no governor the people shall fall" (Pr 11,14).But in the second way the other sacraments are necessary. For in a sense Confirmation perfects Baptism; Extreme Unction perfects Penance; while Matrimony, by multiplying them, preserves the numbers in the Church.
Reply to Objection: 1. For a thing not to be superfluous it is enough if it be necessary either in the first or the second way. It is thus that the sacraments are necessary, as stated above.
2. These words of our Lord are to be understood of spiritual, and not of merely sacramental, eating, as Augustine explains (Tract. xxvi super Joan.).
3. Although contempt of any of the sacraments is a hindrance to salvation, yet it does not amount to contempt of the sacrament, if anyone does not trouble to receive a sacrament that is not necessary for salvation. Else those who do not receive orders, and those who do not contract Matrimony, would be guilty of contempt of those sacraments.
We have now to consider each sacrament specially: (1) Baptism; (2) Confirmation; (3) the Eucharist; (4) Penance; (5) Extreme Unction; (6) Order; (7) Matrimony.
Concerning the first, our consideration will be twofold: (1) of Baptism itself; (2) of things preparatory to Baptism.
Concerning the first, four points arise for our consideration: (1) Things pertaining to the sacrament of Baptism; (2) The minister of this sacrament; (3) The recipients of this sacrament; (4) The effect of this sacrament.
Concerning the first there are twelve points of inquiry:
(1) What is Baptism? Is it a washing?
(2) Of the institution of this sacrament;
(3) Whether water be the proper matter of this sacrament?
(4) Whether plain water be required?
(5) Whether this be a suitable form of this sacrament: "I baptize thee in the name of the Father, and of the Son, and of the Holy Ghost"?
(6) Whether one could baptize with this form: "I baptize thee in the name of Christ?"
(7) Whether immersion is necessary for Baptism?
(8) Whether trine immersion is necessary?
(9) Whether Baptism can be reiterated?
(10) Of the Baptismal rite;
(11) Of the various kinds of Baptism;
(12) Of the comparison between various Baptisms.
Objection: 1. It seems that Baptism is not the mere washing. For the washing of the body is something transitory: but Baptism is something permanent. Therefore Baptism is not the mere washing; but rather is it "the regeneration, the seal, the safeguarding, the enlightenment," as Damascene says (De Fide Orth. iv).
2. Further, Hugh of St. Victor says (De Sacram. ii) that "Baptism is water sanctified by God's word for the blotting out of sins." But the washing itself is not water, but a certain use of water.
3. Further, Augustine says (Tract. lxxx super Joan.): "The word is added to the element, and this becomes a sacrament." Now, the element is the water. Therefore Baptism is the water and not the washing.
On the contrary It is written (Si 34,30): "He that washeth himself [baptizatur] after touching the dead, if he touch him again, what does his washing avail?" It seems, therefore, that Baptism is the washing or bathing.
I answer that In the sacrament of Baptism, three things may be considered: namely, that which is "sacrament only"; that which is "reality and sacrament"; and that which is "reality only." That which is sacrament only, is something visible and outward; the sign, namely, of the inward effect: for such is the very nature of a sacrament. And this outward something that can be perceived by the sense is both the water itself and its use, which is the washing. Hence some have thought that the water itself is the sacrament: which seems to be the meaning of the passage quoted from Hugh of St. Victor. For in the general definition of a sacrament he says that it is "a material element": and in defining Baptism he says it is "water."But this is not true. For since the sacraments of the New Law effect a certain sanctification, there the sacrament is completed where the sanctification is completed. Now, the sanctification is not completed in water; but a certain sanctifying instrumental virtue, not permanent but transient, passes from the water, in which it is, into man who is the subject of true sanctification. Consequently the sacrament is not completed in the very water, but in applying the water to man, i.e. in the washing. Hence the Master (iv, 3) says that "Baptism is the outward washing of the body done together with the prescribed form of words."The Baptismal character is both reality and sacrament: because it is something real signified by the outward washing; and a sacramental sign of the inward justification: and this last is the reality only, in this sacrament---namely, the reality signified and not signifying.
Reply to Objection: 1. That which is both sacrament and reality---i.e. the character---and that which is reality only---i.e. the inward justification---remain: the character remains and is indelible, as stated above (Question [63], Article [5]); the justification remains, but can be lost. Consequently Damascene defined Baptism, not as to that which is done outwardly, and is the sacrament only; but as to that which is inward. Hence he sets down two things as pertaining to the character---namely, "seal" and "safeguarding"; inasmuch as the character which is called a seal, so far as itself is concerned, safeguards the soul in good. He also sets down two things as pertaining to the ultimate reality of the sacrament---namely, "regeneration" which refers to the fact that man by being baptized begins the new life of righteousness; and "enlightenment," which refers especially to faith, by which man receives spiritual life, according to Habac 2 (He 10,38 cf. Habac He 2,4): "But (My) just man liveth by faith"; and Baptism is a sort of protestation of faith; whence it is called the "Sacrament of Faith." Likewise Dionysius defined Baptism by its relation to the other sacraments, saying (Eccl. Hier. ii) that it is "the principle that forms the habits of the soul for the reception of those most holy words and sacraments"; and again by its relation to heavenly glory, which is the universal end of all the sacraments, when he adds, "preparing the way for us, whereby we mount to the repose of the heavenly kingdom"; and again as to the beginning of spiritual life, when he adds, "the conferring of our most sacred and Godlike regeneration."
2. As already stated, the opinion of Hugh of St. Victor on this question is not to be followed. Nevertheless the saying that "Baptism is water" may be verified in so far as water is the material principle of Baptism: and thus there would be "causal predication."
3. When the words are added, the element becomes a sacrament, not in the element itself, but in man, to whom the element is applied, by being used in washing him. Indeed, this is signified by those very words which are added to the element, when we say: "I baptize thee," etc.
Objection: 1. It seems that Baptism was instituted after Christ's Passion. For the cause precedes the effect. Now Christ's Passion operates in the sacraments of the New Law. Therefore Christ's Passion precedes the institution of the sacraments of the New Law: especially the sacrament of Baptism since the Apostle says (Rm 6,3): "All we, who are baptized in Christ Jesus, are baptized in His death," etc.
2. Further, the sacraments of the New Law derive their efficacy from the mandate of Christ. But Christ gave the disciples the mandate of Baptism after His Passion and Resurrection, when He said: "Going, teach ye all nations, baptizing them in the name of the Father," etc. (Mt 28,19). Therefore it seems that Baptism was instituted after Christ's Passion.
3. Further, Baptism is a necessary sacrament, as stated above (Question [65], Article [4]): wherefore, seemingly, it must have been binding on man as soon as it was instituted. But before Christ's Passion men were not bound to be baptized: for Circumcision was still in force, which was supplanted by Baptism. Therefore it seems that Baptism was not instituted before Christ's Passion.
On the contrary Augustine says in a sermon on the Epiphany (Append. Serm., clxxxv): "As soon as Christ was plunged into the waters, the waters washed away the sins of all." But this was before Christ's Passion. Therefore Baptism was instituted before Christ's Passion.
I answer that As stated above (Question [62], Article [1]), sacraments derive from their institution the power of conferring grace. Wherefore it seems that a sacrament is then instituted, when it receives the power of producing its effect. Now Baptism received this power when Christ was baptized. Consequently Baptism was truly instituted then, if we consider it as a sacrament. But the obligation of receiving this sacrament was proclaimed to mankind after the Passion and Resurrection. First, because Christ's Passion put an end to the figurative sacraments, which were supplanted by Baptism and the other sacraments of the New Law. Secondly, because by Baptism man is "made conformable" to Christ's Passion and Resurrection, in so far as he dies to sin and begins to live anew unto righteousness. Consequently it behooved Christ to suffer and to rise again, before proclaiming to man his obligation of conforming himself to Christ's Death and Resurrection.
Reply to Objection: 1. Even before Christ's Passion, Baptism, inasmuch as it foreshadowed it, derived its efficacy therefrom; but not in the same way as the sacraments of the Old Law. For these were mere figures: whereas Baptism derived the power of justifying from Christ Himself, to Whose power the Passion itself owed its saving virtue.
2. It was not meet that men should be restricted to a number of figures by Christ, Who came to fulfil and replace the figure by His reality. Therefore before His Passion He did not make Baptism obligatory as soon as it was instituted; but wished men to become accustomed to its use; especially in regard to the Jews, to whom all things were figurative, as Augustine says (Contra Faust. iv). But after His Passion and Resurrection He made Baptism obligatory, not only on the Jews, but also on the Gentiles, when He gave the commandment: "Going, teach ye all nations."
3. Sacraments are not obligatory except when we are commanded to receive them. And this was not before the Passion, as stated above. For our Lord's words to Nicodemus (Jn 3,5), "Unless a man be born again of water and the Holy Ghost, he cannot enter into the kingdom of God, seem to refer to the future rather than to the present."
Objection: 1. It seems that water is not the proper matter of Baptism. For Baptism, according to Dionysius (Eccl. Hier. v) and Damascene (De Fide Orth. iv), has a power of enlightening. But enlightenment is a special characteristic of fire. Therefore Baptism should be conferred with fire rather than with water: and all the more since John the Baptist said when foretelling Christ's Baptism (Mt 3,11): "He shall baptize you in the Holy Ghost and fire."
2. Further, the washing away of sins is signified in Baptism. But many other things besides water are employed in washing, such as wine, oil, and such like. Therefore Baptism can be conferred with these also; and consequently water is not the proper matter of Baptism.
3. Further, the sacraments of the Church flowed from the side of Christ hanging on the cross, as stated above (Question [62], Article [5]). But not only water flowed therefrom, but also blood. Therefore it seems that Baptism can also be conferred with blood. And this seems to be more in keeping with the effect of Baptism, because it is written (Ap 1,5): "(Who) washed us from our sins in His own blood."
4. Further, as Augustine (cf. Master of the Sentences, iv, 3) and Bede (Exposit. in Luc. iii, 21) say, Christ, by "the touch of His most pure flesh, endowed the waters with a regenerating and cleansing virtue." But all waters are not connected with the waters of the Jordan which Christ touched with His flesh. Consequently it seems that Baptism cannot be conferred with any water; and therefore water, as such, is not the proper matter of Baptism.
5. Further, if water, as such, were the proper matter of Baptism, there would be no need to do anything to the water before using it for Baptism. But in solemn Baptism the water which is used for baptizing, is exorcized and blessed. Therefore it seems that water, as such, is not the proper matter of Baptism.
On the contrary our Lord said (Jn 3,5): "Unless a man be born again of water and the Holy Ghost, he cannot enter into the kingdom of God."
I answer that By Divine institution water is the proper matter of Baptism; and with reason. First, by reason of the very nature of Baptism, which is a regeneration unto spiritual life. And this answers to the nature of water in a special degree; wherefore seeds, from which all living things, viz. plants and animals are generated, are moist and akin to water. For this reason certain philosophers held that water is the first principle of all things.Secondly, in regard to the effects of Baptism, to which the properties of water correspond. For by reason of its moistness it cleanses; and hence it fittingly signifies and causes the cleansing from sins. By reason of its coolness it tempers superfluous heat: wherefore it fittingly mitigates the concupiscence of the fomes. By reason of its transparency, it is susceptive of light; hence its adaptability to Baptism as the "sacrament of Faith."Thirdly, because it is suitable for the signification of the mysteries of Christ, by which we are justified. For, as Chrysostom says (Hom. xxv in Joan.) on Jn 3,5, "Unless a man be born again," etc., "When we dip our heads under the water as in a kind of tomb our old man is buried, and being submerged is hidden below, and thence he rises again renewed."Fourthly, because by being so universal and abundant, it is a matter suitable to our need of this sacrament: for it can easily be obtained everywhere.
Reply to Objection: 1. Fire enlightens actively. But he who is baptized does not become an enlightener, but is enlightened by faith, which "cometh by hearing" (Rm 10,17). Consequently water is more suitable, than fire, for Baptism.But when we find it said: "He shall baptize you in the Holy Ghost and fire," we may understand fire, as Jerome says (In Matth. ii), to mean the Holy Ghost, Who appeared above the disciples under the form of fiery tongues (Ac 2,3). Or we may understand it to mean tribulation, as Chrysostom says (Hom. iii in Matth.): because tribulation washes away sin, and tempers concupiscence. Or again, as Hilary says (Super Matth. ii) that "when we have been baptized in the Holy Ghost," we still have to be "perfected by the fire of the judgment."
2. Wine and oil are not so commonly used for washing, as water. Neither do they wash so efficiently: for whatever is washed with them, contracts a certain smell therefrom; which is not the case if water be used. Moreover, they are not so universal or so abundant as water.
3. Water flowed from Christ's side to wash us; blood, to redeem us. Wherefore blood belongs to the sacrament of the Eucharist, while water belongs to the sacrament of Baptism. Yet this latter sacrament derives its cleansing virtue from the power of Christ's blood.
4. Christ's power flowed into all waters, by reason of, not connection of place, but likeness of species, as Augustine says in a sermon on the Epiphany (Append. Serm. cxxxv): "The blessing that flowed from the Saviour's Baptism, like a mystic river, swelled the course of every stream, and filled the channels of every spring."
5. The blessing of the water is not essential to Baptism, but belongs to a certain solemnity, whereby the devotion of the faithful is aroused, and the cunning of the devil hindered from impeding the baptismal effect.
Objection: 1. It seems that plain water is not necessary for Baptism. For the water which we have is not plain water; as appears especially in sea-water, in which there is a considerable proportion of the earthly element, as the Philosopher shows (Meteor. ii). Yet this water may be used for Baptism. Therefore plain and pure water is not necessary for Baptism.
2. Further, in the solemn celebration of Baptism, chrism is poured into the water. But this seems to take away the purity and plainness of the water. Therefore pure and plain water is not necessary for Baptism.
3. Further, the water that flowed from the side of Christ hanging on the cross was a figure of Baptism, as stated above (Article [3], ad 3). But that water, seemingly, was not pure, because the elements do not exist actually in a mixed body, such as Christ's. Therefore it seems that pure or plain water is not necessary for Baptism.
4. Further, lye does not seem to be pure water, for it has the properties of heating and drying, which are contrary to those of water. Nevertheless it seems that lye can be used for Baptism; for the water of the Baths can be so used, which has filtered through a sulphurous vein, just as lye percolates through ashes. Therefore it seems that plain water is not necessary for Baptism.
5. Further, rose-water is distilled from roses, just as chemical waters are distilled from certain bodies. But seemingly, such like waters may be used in Baptism; just as rain-water, which is distilled from vapors. Since, therefore, such waters are not pure and plain water, it seems that pure and plain water is not necessary for Baptism.
On the contrary The proper matter of Baptism is water, as stated above (Article [3]). But plain water alone has the nature of water. Therefore pure plain water is necessary for Baptism.
I answer that Water may cease to be pure or plain water in two ways: first, by being mixed with another body; secondly, by alteration. And each of these may happen in a twofold manner; artificially and naturally. Now art fails in the operation of nature: because nature gives the substantial form, which art cannot give; for whatever form is given by art is accidental; except perchance when art applies a proper agent to its proper matter, as fire to a combustible; in which manner animals are produced from certain things by way of putrefaction.Whatever artificial change, then, takes place in the water, whether by mixture or by alteration, the water's nature is not changed. Consequently such water can be used for Baptism: unless perhaps such a small quantity of water be mixed artificially with a body that the compound is something other than water; thus mud is earth rather than water, and diluted wine is wine rather than water.But if the change be natural, sometimes it destroys the nature of the water; and this is when by a natural process water enters into the substance of a mixed body: thus water changed into the juice of the grape is wine, wherefore it has not the nature of water. Sometimes, however, there may be a natural change of the water, without destruction of species: and this, both by alteration, as we may see in the case of water heated by the sun; and by mixture, as when the water of a river has become muddy by being mixed with particles of earth.We must therefore say that any water may be used for Baptism, no matter how much it may be changed, as long as the species of water is not destroyed; but if the species of water be destroyed, it cannot be used for Baptism.
Reply to Objection: 1. The change in sea-water and in other waters which we have to hand, is not so great as to destroy the species of water. And therefore such waters may be used for Baptism.
2. Chrism does not destroy the nature of the water by being mixed with it: just as neither is water changed wherein meat and the like are boiled: except the substance boiled be so dissolved that the liquor be of a nature foreign to water; in this we may be guided by the specific gravity [spissitudine]. If, however, from the liquor thus thickened plain water be strained, it can be used for Baptism: just as water strained from mud, although mud cannot be used for baptizing.
3. The water which flowed from the side of Christ hanging on the cross, was not the phlegmatic humor, as some have supposed. For a liquid of this kind cannot be used for Baptism, as neither can the blood of an animal, or wine, or any liquid extracted from plants. It was pure water gushing forth miraculously like the blood from a dead body, to prove the reality of our Lord's body, and confute the error of the Manichees: water, which is one of the four elements, showing Christ's body to be composed of the four elements; blood, proving that it was composed of the four humors.
4. Baptism may be conferred with lye and the waters of Sulphur Baths: because such like waters are not incorporated, artificially or naturally, with certain mixed bodies, and suffer only a certain alteration by passing through certain bodies.
5. Rose-water is a liquid distilled from roses: consequently it cannot be used for Baptism. For the same reason chemical waters cannot be used, as neither can wine. Nor does the comparison hold with rain-water, which for the most part is formed by the condensing of vapors, themselves formed from water, and contains a minimum of the liquid matter from mixed bodies; which liquid matter by the force of nature, which is stronger than art, is transformed in this process of condensation into real water, a result which cannot be produced artificially. Consequently rain-water retains no properties of any mixed body; which cannot be said of rose-water or chemical waters.
Summa Th. III EN Qu.65 a.2