New Blackfriars 20, September 2016 (online DOI:10.1111/nbfr.12154) and 98, November 2017: 689-708 (print version)
It appears that many theologians today either do not have a clear understanding of the metaphysics of participation (leaving that up to the philosophers) or do not see the importance of participation with regard to the bearing that it has on theology, particularly within the realm of Christology and grace. This is unfortunate, because without an understanding of sanctifying grace as an ontological participation in the life of God, Christians are left with the idea of justification as a simple “covering over” of sin, without any real transformation taking place in the soul. Nevertheless, as we will see, the notion of participation is actually operative throughout the thought of St. Thomas and within the Catholic understanding of the creature’s relationship to God—in particular, with regard to sanctifying grace.
Analogy of Being
Before speaking any further about participation, however, it is important to understand something of St. Thomas’ view of analogy with regard to being, and consequently, with regard to the transcendentals, and to the supernatural life of grace, as well.
In his Commentary on Aristotle’s Metaphysics, Aquinas clearly illustrates the three principal ways in which one thing can be predicated of another: univocally, equivocally and analogously. In explaining the first two ways, he states:
In the case of univocity one term is predicated of different things with absolutely one and the same meaning; for example, the term animal, which is predicated of a horse and of an ox, signifies a living, sensory substance. In the case of equivocity the same term is predicated of various things with an entirely different meaning. This is clear in the case of the term dog, inasmuch as it is predicated both of a constellation and of a certain species of animal. 
Before beginning his explanation of the third mode of predication, i.e. by way of analogy, Aquinas refers to Aristotle’s example of the term, “healthy”, which, St. Thomas says, can refer both to one thing, such as urine, which is a sign of health, and to another thing, such as medicine, which causes health:
But…[when] the same term is predicated of various things with a meaning that is partly the same and partly different—different regarding the different modes of relation, and the same regarding that to which it is related; for to be a sign of something and to be the cause of something are different, but health is one. Terms of this kind, then, are predicated analogously, because they have a proportion to one thing.
Aquinas then goes on to explain that the same holds true with regard to “being” (ens), which, simply speaking, can refer to a substance (“that which has being [i.e. esse] in itself”), but in a less proper way can also refer to an accident, which “belongs to” that which has being through itself, i.e. that which inheres in the substance.
But what about with regard to God Himself? How do we predicate “being” both of God and of a creature? First of all, Aquinas points out in De Veritate that nothing can be predicated univocally of God and a creature, because, he explains,
…for in all univocal things, the definition of a name is common to both of those things concerning which the name is univocally predicated; and thus as pertains to the definition of that name, univocal things are equal in some way (although according to being, one thing may be prior or posterior to another).…
Here Aquinas gives the example of numbers, which all have the nature of a number, even though one may be naturally prior or posterior to another. However, as Aquinas points out, no matter how much a creature may imitate God, it will never reach a point in which something may belong both to it and to God in the same respect. That is, in the case of creatures, it is possible for them to share a certain formality with regard to substance or essence, though they are distinct with regard to being, but God is His own Act of Being and His essence is the same as His Act of Being. Therefore, just as one creature cannot communicate his own act of being to another, likewise it is impossible for a creature to possess some attribute in the same way that God possesses it.
Nevertheless, says Thomas, this does not mean that a creature is doomed to a purely equivocal predication with regard to itself and God, otherwise we could not say that there was any real likeness of God in creatures at all, and we would not be able to attain to any real knowledge of God from His effects. Therefore, there are some attributes which can be predicated analogously of God and creatures, though they must be, as Aquinas explains, “all things in whose definition is not included a defect, nor [things which] depend on matter for being [esse], such as being [ens], good, and other things of this sort.”
A Metaphysical Notion of Participation
Fr. Cornelio Fabro, an Italian Thomistic philosopher, points out that “participation” can have multiple senses. It can refer to a participation in the quantitative and material order, as in participating in a pizza, in which the “whole” is divided and distributed in parts (resulting, however, in a diminishing of the whole as pieces are taken from the pizza, for example), or it can refer to a metaphysical notion of participation, which “concerns properly speaking the mode of having and receiving, in the sense that the ‘whole’ remains intact and undivided, while an aspect or form of the object is being participated.” This would be the case, for example, in which one participates in “goodness” or “whiteness”, without causing any diminishment to the forms of “goodness” or “whiteness” as a result.
Let us begin with a basic understanding, then, of the etymological explanation Aquinas gives of participation. Aquinas clearly defines participare in De hebdomadibus, where he says, “To participate is, as it were, to take part, and therefore, when something receives partially that which belongs to another universally, it is said to participate in that, just as man is said to participate in animal, because he does not have the notion of animal according to the whole commonality.” In other words, to participate in something is to have a share in it in some way, as in the case of the essence of man, who is, according to Aristotle, a “rational animal”, whereby man participates in the genus of “animal”, without containing in himself the totality of all animality (since other creatures are also said to belong to this genus).
However, it is important to note here that in speaking of participation in genus and species, St. Thomas is not adopting a Platonic view that the genus or species have a real existence separate from those that participate in them. With regard to any ontological content, one must say with Fabro that the genus and species
are present in their respective subjects and must therefore be predicated essentially [i.e. as part of the definition]… and not by participation…. [However,] With regard to the mode of being (and therefore the mode of being actualized in a concrete reality) a genus is differently actualized in the various species according to different degrees of perfection….Thus participation involves no doubt a univocal nature or essence but only insofar as this is raised to a metaphysical level and considered as a “whole”, that is, as a complex of virtual perfections that are being divided into or participated by the various species (for the genus) and the many individuals (for the species)….
Aquinas explains further what he means by participation in his Commentary on the Metaphysics of Aristotle. He writes, “For that which is something in its entirety does not participate in it but is essentially identical with it, whereas that which is not something in its entirety but has this other thing joined to it, is said properly to participate in that thing.” He then proceeds to give the example of heat, “which if it were heat existing through itself, would not be said to participate in heat, because nothing would be in it but heat,” whereas fire, because it is something other than heat, can be said to participate in heat. In other words, participation for St. Thomas means to have an act or formality in a limited, imperfect, particular way, which is received from one who has it in an unlimited, perfect and universal way.
In De hebdomadibus, Aquinas presents three types of participation, the first two of which were mentioned above: 1) logical / notional participation, i.e., a species participates in a genus, and an individual in a species (as in our first example of man participating in the genus of animal); 2) a real participation, i.e. a substance participates in an accident, and matter in a form (as in our second example of fire participating in heat); and finally, 3) a causal participation, i.e. the effect participates in its own cause.
Without getting into the various types of causes, it is important to emphasize this relationship between participation and causality. As Aquinas points out, “Whatever is found in anything by participation, must be caused in it by that to which it belongs essentially…” Then, after noting that God is Ipsum Esse per se subsistens, Aquinas adds, “Therefore all beings apart from God are not their own being, but are beings by participation. Therefore it must be that all things which are diversified by the diverse participation in being,… are caused by one First Being, Who possesses being most perfectly.” Here we begin to understand something of Divine Causality as the source of participation.
Fr. Cornelio Fabro also distinguishes another type of grouping of participation in St. Thomas, which he terms predicamentale-univoco and trascendentale-analogo. He explains that in the univocal-predicamental participation, “All the participants have in themselves the same formality as to the whole of its essential content, and the participated thing does not exist in itself, but only in the participants.” For example, “humanity” does not exist outside of the human beings in which it is found univocally.
However, in the case of analogous-transcendental participation, Fabro points out that “the participants have in themselves only a ‘down-graded likeness’ of the participated thing which subsists in itself, outside of these, either as a property of a superior subsistent, or certainly, as a pure and subsistent formality in full possession of itself.”  This is the most intense meaning of participation, already found in Plato, and taken up by St. Thomas. This analogous participation, says Fabro, “…is that of the creature from the Creator which, being esse by essence, sums up in Himself all the other perfections, formally if they are pure perfections, virtually if mixed.”
It is important to recognize the existence of this analogous participation in order to maintain the transcendence of God. Creatures do not share being with God in a univocal way, nor in a completely equivocal manner. As Cavanaugh points out,
For Aquinas… it is the rejection of the univocity of being that allows the participation of the human in the divine. For precisely because God is entirely transcendent to creaturely being, because God is not another being in competition with finite being, God is the only agent who acts immediately—that is, through no medium—in all things (I.8.1, ad 3).
According to Fabro, causality can be understood as predicamental participation (“concerned with fieri, which is the becoming or development of created reality within the order of genera and species”) or transcendental participation (which “extends to both creation and conservation, to form as well as to matter”). In this latter sense, “the form is the true cause of esse, but only within its order, inasmuch as it is the predicamental mediator between created finite being and the esse per essentiam, which is the First Cause.”
Participation in Being and Image
It is important to note that Aquinas understands participation within the Aristotelian framework of act and potency. In the Summa, Aquinas explains, “Everything participated is compared to the participator as its act.” The Angelic Doctor goes on to explain that every created form must participate in esse, but one’s degree of participation is limited by the capacity of the one participating. Whence, he says, “…only God, who is His own esse itself, is pure and infinite act,” whereas the intellectual substances (and the rest of creation) are limited in esse according to their capacities to receive it, i.e., they are a composition of act and potency, participating in that esse. Rziha notes, “Thus, in Thomistic thought, participation is a sharing in the essential act of another, which is limited by the potency of the participating subject.”
In Thomas’ understanding of participation within this Aristotelian framework, Rziha points out that act is to be understood as a perfection. He explains, “Humans are perfected by that act of esse that takes part in the esse of God. Yet even here Thomas goes beyond Aristotle by seeing potency as the capacity to receive perfection and seeing act as the perfection of esse.” Therefore, for Aquinas, the essence of a corporeal creature, although composed of matter and form (which functions as potency to act) is itself also related to esse as potency to act. This holds true for non-corporeal creatures, as well, which participate in esse (and are not their own esse), and so must be said to be composed of potency and act even though they contain no matter.
Therefore, all creatures participate in God’s esse, “…because God is called a Being [ens] in this way, that He is His own being [esse] itself; a creature, however, is not its own being [esse] itself, but is called a being [ens] as participating in being [esse].” As Fabro notes, a formality can exist and be predicated either per essenza or per partecipazione. God, of course, is His own Esse by essence, whereas creatures only receive esse by participation.
Here, however, we should note the distinction between esse commune and the Divine esse. As Wippel explains, for St. Thomas, the esse commune “is that intrinsic principle, that act of being, found in every existing entity, that is, every substance, which accounts for the fact that it actually exists.” In other words, all creatures depend on the esse commune for their existence, whereas the esse commune (i.e., created being) depends on God (Uncreated Subsistent Being Itself) as its cause and principle. Wippel notes, “In participating in the esse which is efficiently communicated to it by God, the creature may also be said to participate in some way in God, that is, in his likeness.”
However, Aquinas indicates that man shares in a certain likeness to God which is different from that of irrational creatures. He explains:
The likeness of image is found in human nature, forasmuch as it is capable of God [capax Dei]—viz., by attaining to Him through its own operation of knowledge and love. But the likeness of trace regards only a representation of the Divine impression, existing in the creature, and does not imply that the irrational creature, in which such a likeness is, can attain to God by its own operation alone.
Cessario describes the three stages of this image as found in man, known as the “imago Dei.” The first stage is that of the Natural Image, by which man loves God in the natural order “inasmuch as He is the beginning and the end of natural good,” without the help of sanctifying grace. Man alone has, as St. Thomas puts it, a certain natural capacity for God, because man is created with an openness and potential to attaining to universal truths and to universal goods, taken distributively, and is thereby rendered capable of being elevated to God (the Universal True and the Universal Good par excellence) by means of grace.
Now the created rational nature alone is immediately subordinate to God, since other creatures do not attain to the universal, but only to something particular, while they partake of the Divine Goodness either in “being” only as inanimate things, or also in “living”, and in “knowing singulars”, as plants and animals; whereas the rational nature, in as much as it apprehends the universal notion of good and being, is immediately related to the universal principle of being. Consequently the perfection of the rational creature consists not only in what belongs to it in respect of its nature, but also in that which it acquires through a supernatural participation of Divine goodness.
This leads us to the second stage, the Image of Grace, also known as the imago Christi, which is a supernatural participation in God’s goodness and nature that comes to us through Christ.
However, we should first note that man already has a certain natural participation in goodness, because in participating in God’s esse, man also participates in the other transcendentals which are convertible with being and transcend all particular categories of being, being common to all of them. Goodness is one of the commonly-listed transcendentals, along with truth and oneness. Aquinas explains in De Veritate, “In this way an essence is called good, inasmuch as it is a being [ens]; whence just as it has being [esse] by participation, thus it is also good by participation.” In other words, just as God is Esse essentialiter, because only God is subsistent esse, whereas being must be predicated of creatures per participationem, “so also God is called good essentially, because He is goodness itself; however, creatures are called good by participation, because they have goodness….”
Nonetheless, it is the supernatural “participation of the Divine goodness” that is grace, which in turn, prepares the soul for its final conformity to God in beatitude, known as the Image of Glory. Here one should point out that for Aquinas, there are two modes of participation in the divine light, of which faith is the imperfect, yet prior participation, and the vision of glory is the perfect participation. Fabro notes:
The proper and full vision will occur only when, after this life, to whomever dies in grace, will be communicated the light of glory which is, in a certain way, the most proper participation in the vitality itself of God, whence the creature enters into communion with the very object of which God Himself lives. The participation of the “lumen gloriae” tends to complete in an ineffable way this assimilation of the created intellect….
The Image of Glory, therefore, is the highest form of participation possible to a creature, other than that of the hypostatic union itself. In his writings on the Sentences, St. Thomas points out that the “last and most complete participation in His [i.e. God’s] goodness consists in the essential vision of Him [i.e. the Beatific Vision], by which we live together with Him socially as friends, since in that… beatitude consists.”
In participating in the Beatific Vision, Aquinas notes that man will participate in eternity itself, “the simultaneously-whole and perfect possession of unending life,” since in the vision, “all things that are seen through it are seen at once, and in one view.” This participation in eternity consists in a certain unchangeableness in being and operation for those who share in God’s eternal life.
We can sum up these three stages or images in man, therefore, with an explanation from Aquinas:
Wherefore we see that the image of God is in man in three ways. First, inasmuch as man possesses a natural aptitude for understanding and loving God; and this aptitude consists in the very nature of the mind, which is common to all men. Secondly, inasmuch as man actually and habitually knows and loves God, though imperfectly; and this image consists in the conformity of grace. Thirdly, inasmuch as man knows and loves God perfectly; and this image consists in the likeness of glory.
Christ as Head
Fabro points out that when St. Thomas answers the question of whether the lack of original justice gives rise to the notion of guilt in Adam’s descendants, he explains original sin as a sin of nature, by using the concept which Fabro refers to as “predicamental participation.” Aquinas states:
This question is easily solved if we but distinguish between person and nature. As there are many members in one person, so there are many persons in one human nature. Thus, by sharing in the same species, many men may be thought of as one man, as Porphyry remarks… In this way, then, the privation of original justice is a sin of nature, in the sense that it has its origin in the inordinate will of the first principle in human nature, namely, of the first parent. Thus it is voluntary with respect to nature, that is, by the will of the first principle of nature. And so it is transmitted to all who receive human nature from him, for they are all, as it were, his members.
In a similar way, Aquinas uses the idea of predicamental participation in speaking of how Christ could merit for others. He explains that Christ is the Head of the Church, and even goes so far as to say “Christ and the Church are as one person,” and he later adds, “Christ could therefore merit for the faithful as for His own members….” Likewise, in speaking of the efficiency of Christ’s passion, Aquinas notes:
Grace was bestowed upon Christ, not only as an individual, but inasmuch as He is the Head of the Church, so that it might overflow into His members; and therefore Christ’s works are referred to Himself and to His members in the same way as the works of any other man in a state of grace are referred to himself.”
In fact, Fabro points out that the Incarnation began a new stage in the economy of salvation. Whereas the good angels and our First Parents participated in the gratia Dei (i.e., grace directly from God, given before the Fall),
…the grace of the regenerated men, rather, is participated through Christ, who has merited it. This is, therefore, the “gratia Christi”, and all the gifts which God now effuses into the holy souls are a participation in the fullness of the gifts which is in Him. Christ, therefore, comes to be considered like a new font of supernatural participations.
However, predicamental participation can only explain the mode of our participation in grace, i.e., through Christ, and not what grace is in itself, which, as Aquinas notes, “is nothing short of a partaking in the Divine Nature.” Participation in the divine esse, as we have said, is an analogous-transcendental participation, and in this way, grace is a new creation. Therefore, it would appear that the grace of the Holy Spirit which we receive through Christ is an analogous-transcendental participation in God’s own life, but it remains a sort of predicamental participation in the way that we receive it, which is by being united to Christ as members of His Mystical Body.
However, we must not understand this to mean that Christ Himself is merely a participant in God’s life. In fact, the head or source of a perfection does not itself participate in the perfection of the genus, because it is the cause of that perfection. Aquinas explains:
So that has life in itself which has an essential, non-participated life, i.e., that which is itself life. Now in every genus of things, that which is something through its essence is the cause of those things that are it by participation, as fire is the cause of all things afire. And so, that which is life through its essence, is the cause and principle of all life in living things. Accordingly, if something is to be a principle of life, it must be life through its essence. And so our Lord fittingly shows that he is the principle of all life by saying that he has life in himself, i.e., through his essence, when he says: just as the Father possesses life in himself, i.e., as he is living through his essence, so does the Son.
Therefore, the primary source of all participation in the life of grace is Christ, as Head of the Church. Nevertheless, Aquinas also observes that “…the soul of Christ is not Divine by its essence. Whence it is necessary that it be made Divine by participation, which is according to grace.” Consequently, although in the Person of the Word, Christ is the natural Son of God, His humanity needed to “attain to God by a created act of fruition which indeed cannot be except by grace.” In other words, in order for Christ, in his human operation, to cooperate with the Divine operation, it was necessary for Christ to have habitual grace.
Participation in the Grace of Christ
In the hypostatic union, Christ’s human nature is made to participate in the life of the Divine Person of the Son, with the result that, as Fabro explains, “This [union] has become the primary source of all participation in grace by believers inasmuch as the human nature of Christ is the close instrument of the divinity.” This is important, because, as Aquinas notes, “…therefore His actions could be salutary for us.” In other words, Christ’s humanity serves as an instrumental cause, moved by the principle agent of His Divinity:
The Divine Nature makes use of the operation of the human nature, as of the operation of its instrument; and similarly, the human nature participates in the operation of the Divine nature, just as an instrument participates in the operation of the principle agent.
St. Thomas also notes that the personal grace by which the soul of Christ was justified is essentially the same as the grace by which He is the Head of the Church, allowing for a distinction of reason. He observes, “…in the soul of Christ, grace was received in the highest way. And therefore, from that pre-eminence of grace which He received, it belongs to Him that grace is bestowed on others, which pertains to the nature of Head.”
It is important to note that the first and most important way in which we can participate in Christ is by means of divine sonship. Christ is the natural Son of God by the grace of union, and we are called to participate in that divine filiation, and so become the adopted sons of God by means of habitual grace, which is both created and an accident in us. As Aquinas states, “…the sonship of adoption is a participated likeness of natural sonship….”
In other words, Christ, as Perfect God and Perfect Man, has become the mediator uniting us to God, “by communicating to men both precepts and gifts, and by offering satisfaction and prayers to God for men.” The principle gift given to men is grace, which is chiefly bestowed on us through the sacraments. The Angelic Doctor explains:
As in the person of Christ the humanity causes our salvation by grace, the Divine power being the principal agent, so likewise in the sacraments of the New Law, which are derived from Christ, grace is instrumentally caused by the sacraments, and principally by the power of the Holy Ghost working in the sacraments….
It is through the sacraments, of course, that the soul participates in the divine sonship, with the sacrament of Baptism being “the gateway to life in the Spirit (vitae spiritualis ianua), and the door which gives access to the other sacraments.” Baptism, then, is the primary source of grace, which, “in the very essence of the soul by means of a kind of indwelling, is the root and cause of infused virtue.” In fact, the theological, as indeed all the infused virtues, are given to the soul at baptism, and not only are original and personal sin removed from the soul, but the person is also incorporated into the Mystical Body of Christ, which incorporation allows each one to participate in the grace of Christ as if it were his own.
However, Aquinas is careful to distinguish the instrumental agency of the sacraments from that of Christ’s humanity, explaining that an instrument can either be united (as one’s hand is united to the body) or separate (as a stick, for example). The separate instrument is always moved by the principal agent by means of the united instrument. Therefore, St. Thomas is able to explain the causality of the sacraments:
Now the principal efficient cause of grace is God Himself, in comparison with Whom Christ’s humanity is as a united instrument, whereas the sacrament is as a separate instrument. Consequently, the saving power must needs be derived by the sacraments from Christ’s Godhead through His humanity.
Yet one might ask what makes the sacraments so efficacious. Aquinas points out that it is Christ’s Passion. He explains, for example, “The heavens were opened at Christ’s baptism, not for Christ’s sake, to whom heaven was ever open, but in order to signify that heaven is opened to the baptized, through Christ’s baptism, which has its efficacy from His Passion.” In another place, speaking of Christ’s Passion as the “universal cause for the forgiveness of sins,” Aquinas adds that “this is done by baptism and penance and the other sacraments, which derive their power from Christ’s Passion….”
Of course, the sacraments do not come to us without the Church which Christ founded. The Mystical Body of Christ is not a merely invisible incorporation, but involves a visible community, which often comes together to participate in the grace given through the various sacraments. As Levering points out, “For Aquinas, in short, the sacraments create a visible community whose purpose it is to mediate participation in Christ’s passion.”
Justification by Grace
The Council of Trent, in speaking of the causes of our justification, explains that the meritorious cause is Christ, who “merited for us justification by his most holy Passion on the wood of the Cross [can. 10] and made satisfaction for us to God the Father.” The Council then goes on to name baptism as the instrumental cause. Therefore, Christ has merited the First Grace of justification for us, inasmuch as we participate in His Passion (particularly in baptism, in which we “die with Christ”—cf. Rm 6:8), but we are also able to merit future graces in union with Christ. Levering explains, “Cooperating with grace, we become just through the works that grace enables us to perform. The source of our justification, ultimately, is not our own works but Christ’s meritorious justice, which we share in by grace.” In fact, the Council of Trent declares that we are justified by the justice of God, in the sense that He makes us formally just, spiritually renewing us:
…not only are we considered just, but we are truly called just and we are just [cf. 1 Jn 3:1], each one receiving within himself his own justice, according to the measure that “the Holy Spirit apportions to each one individually as he wills” [cf. 1 Cor 12:11] and according to each one’s personal disposition and cooperation.
In other words, Catholics believe that the justification of Christ is not a merely outward imputation of justice, but a true, inward inherence of the grace of justification in the soul, which renews and sanctifies it by making it participate in God’s own life. In speaking of grace as the principal effect of the sacraments, Aquinas cites the second letter of St. Peter which states:
His divine power has granted to us all things that pertain to life and godliness, through the knowledge of him who called us to his own glory and excellence, by which he has granted to us his precious and very great promises, that through these you may escape from the corruption that is in the world because of passion, and become partakers of the divine nature.
Aquinas explains that Christ’s suffering and death not only delivers us from original sin, but also “from the personal sins of individuals who share in His Passion by faith and charity and the sacraments of faith.” It is the theological virtue of charity, in particular, which inspired the saints to desire to participate in Christ’s Passion and through which grace is the principle of merit for us. In fact, our love for God and neighbor is itself a participation in the Divine charity:
Wherefore just as we are said to be good with the goodness which is God, and wise with the wisdom which is God (since the goodness whereby we are formally good is a participation of Divine goodness, and the wisdom whereby we are formally wise, is a share of Divine wisdom), so too, the charity whereby formally we love our neighbor is a participation of Divine charity.
Of course, the Eucharist is the ultimate sacrament of charity, since by it, we not only participate directly in the sacrifice of Christ on the Cross, but we also receive Love Himself. Aquinas explains the difference in the way one participates in Christ’s Passion through the sacrament of the Eucharist versus that of baptism, saying:
Baptism is the sacrament of Christ’s death and Passion, according as a man is born anew in Christ in virtue of His Passion; but the Eucharist is the sacrament of Christ’s Passion according as a man is made perfect in union with Christ Who suffered. Hence, as Baptism is called the sacrament of Faith, which is the foundation of the spiritual life, so the Eucharist is termed the sacrament of Charity, which is the bond of perfection….
It is, indeed, in the holy sacrifice of the Mass where the members of the Mystical Body of Christ participate most fully in Christ’s saving Passion here on earth, which is at the same time a foreshadowing of and an already real participation in the heavenly liturgy. Aquinas points out that the Eucharistic celebration is “a certain image representative of Christ’s Passion, which is a true immolation,” and the Mass is called a sacrifice “with respect to the effect of His Passion: because, namely, by this sacrament, we are made participants of the fruit of the Lord’s Passion.”
So, then, this sacrament benefits recipients by way both of sacrament and of sacrifice, because it is offered for all who partake of it. For it is said in the Canon of the Mass: May as many of us as, by participation at this Altar, shall receive the most sacred body and blood of Thy Son, be filled with all heavenly benediction and grace.
Esse may be predicated only analogously of God and creatures. Creatures, which have being by participation, receive their being from God, who is Being by essence. Distinct from all irrational creatures, man is created in the image and likeness of God, which involves a natural participation in God’s esse, in which man is made capax Dei, because his intellect is ordained to universal truths and his will to universal goods, so that he is capable of being elevated, unlike other corporeal creatures, to a supernatural participation in God’s goodness, which comes to him through Christ. In fact, Christ Himself becomes the source of grace through the participation of His Humanity in the power of His Divinity, and through our participation in Him as members of a body participate in the Head.
The highest form of participation possible to us is the Beatific Vision. In order to attain to this glory, however, we are called to first participate in divine sonship and in the gifts of virtue and grace which come to us through the sacraments and which are celebrated within the visible community of the Church. The power of the sacraments and the possibility of justification and merit are only made possible through a certain participation in the Passion of Christ, informed by the theological virtue of Charity.
In summary, therefore, it is important to note the significant role the metaphysical notion of participation has in Aquinas’ understanding, not only of creation, but also of the Incarnation and of the whole supernatural life of grace, justification and merit. We have said that grace can be understood as an analogous-transcendental participation in God’s own life which is received as a predicamental participation with respect to Christ as members of His Mystical Body. But it is especially essential to the Catholic understanding of justification to have a proper conception of grace as a causal (and not merely moral) participation in the Divine Nature, and as something which inheres in the soul and really transforms it. Without this appreciation of the true value of grace in the soul, one can easily fall into an extrinsic, forensic view of justification, in which the soul always remains in a helpless state of sin.
 The portrayal of man after being justified as a “dunghill of corruption… covered over as it were with a little snow”, although not found in Luther’s works (who appears, however, to have had a similar understanding of justification), can certainly be found in the writings of Rev. George Whitefield (perhaps among others). See “Letter to Mr. S__”, dated Dec. 13, 1753 in A Select Collection of Letters of the Late Reverend George Whitefield, vol. III (London: Printed for Edward and Charles Dilly, 1772), 47. In addition, according to Joseph Pohle and Arthur Preuss, the supporters of the Augsburg Confession (1530) held the view “that the sinner, by a ‘fiduciary apprehension’ of God’s mercy… ‘apprehends’ the extrinsic justice of Christ, and with it covers his sins, which are thereupon no longer ‘imputed’ to him. In other words, he is outwardly accounted and declared righteous in the sight of God, though inwardly he remains a sinner.” Grace, Actual and Habitual: A Dogmatic Treatise, Dogmatic Theology (Toronto: W.E. Blake & Son, 1919), 310-313.
 St. Thomas Aquinas, Commentary on Aristotle’s Metaphysics, L. XI, lect. 3, n. 2197, transl. by Richard Blackwell et al. (Notre Dame, IN: Dumb Ox Books, 1995; original copyright by Henry Regnery Company, 1961). “In univocis enim nomen unum praedicatur de diversis secundum rationem totaliter eamdem; sicut animal de equo et de bove dictum, significat substantiam animatam sensibilem. In aequivocis vero idem nomen praedicatur de diversis secundum rationem totaliter diversam. Sicut patet de hoc nomine, canis, prout dicitur de stella, et quadam specie animalis.” Latin text from In Metaphysicam Aristotelis Commentaria, ed. Fr. M. R. Cathala (Taurina, Italy: Marietti, 1926).
 Ibidem. “… idem nomen de diversis praedicatur secundum rationem partim eamdem, partim diversam. Diversam quidem quantum ad diversos modos relationis. Eamdem vero quantum ad id ad quod fit relatio. Esse enim significativum, et esse effectivum, diversum est. Sed sanitas una est. Et propter hoc huiusmodi dicuntur analoga, quia proportionantur ad unum.”
 St. Thomas Aquinas, De Veritate, in Quaestiones Disputatae, vol. 1, ed. Fr. Raymundi Spiazzi (Rome, Italy: Marietti, 1949), q.2, a.11, resp. “In omnibus enim univocis communis est ratio nominis utrique eorum de quibus nomen univoce praedicatur; et sic quantum ad illius nominis rationem univoca in aliquo aequalia sunt, quamvis secundum esse unum altero possit esse prius vel posterius….” (English transl. mine.)
 Ibid., “sunt omnia in quorum definitione non clauditur defectus, nec dependent a materia secundum esse, ut ens, bonum, et alia huiusmodi.” (English transl. mine.)
 Fr. Cornelio Fabro, “The Intensive Hermeneutics of Thomistic Philosophy: The Notion of Participation,” The Review of Metaphysics, (transl. by B. M. Bonansea) vol. 27, no. 3 (March 1974), 453.
 St. Thomas Aquinas, An Exposition of the “On the Hebdomads” of Boethius (Washington, D.C.: The Catholic University of American Press, 2001), Lect.2, n.70. “…est autem participare quasi partem capere; et ideo, quando aliquid particulariter recepit id quod ad alterum pertinent, universaliter dicitur participare illud; sicut homo dicitur participare animal, quia non habet rationem animalis secundum totam communitatem.” (English transl. mine.)
 Fabro, “Intensive Hermeneutics of Thomistic Philosophy”, 471-472. (Brackets mine.)
 St. Thomas Aquinas, Commentary on Aristotle’s Metaphysics, L.1, lect. 10, n. 154. “Quod enim totaliter est aliquid, non participat illud, sed est per essentiam idem illi. Quod vero non totaliter est aliquid habens aliquid aliud adiunctum, proprie participare dicitur”. Latin text from In Metaphysicam Aristotelis Commentaria.
 Aquinas, In Metaphysicam Aristotelis Commentaria. “Sicut si calor esset calor per se existens, non diceretur participare calorem, quia nihil esset in eo nisi calor.” (English transl. mine.)
 Rudi A. Te Velde, Participation and Substantiality in Thomas Aquinas (New York, NY: E.J. Brill, 1995), 11-14.
 St. Thomas Aquinas, The Summa Theologiae of Saint Thomas Aquinas, vol. I (Scotts Valley, CA: CreateSpace; NovAntiqua, 2008), I, q.44, a.1, resp. “Si enim aliquid invenitur in aliquo per participationem, necesse est quod causetur in ipso ab eo cui essentialiter convenit…”
 Ibidem, “Relinquitur ergo quod omnia alia a Deo non sint suum esse, sed participant esse. Necesse est igitur omnia quae diversificantur secundum diversam participationem essendi,… causari ab uno primo ente, quod perfectissime est.”
 Fr. Cornelio Fabro, La Nozione Metafisica di Partecipazione [Segni (RM), Italy: Editrice del Verbo Incarnato, 2005], 305.
 Ibidem. “…tutti i partecipanti hanno in sè la stessa formalità secondo tutto il suo contenuto essenziale, ed il partecipato non esiste in sè, ma solo nei partecipanti” (English transl. mine).
 Ibidem. “…i partecipanti non hanno in sè che una ‘similitudine degradata’ del partecipato che sussiste in sè, al di fuori di essi, o come proprietà di un sussistente superiore, o senz’altro come formalità pura e sussistente nella piena possessione di sè.” (English transl. mine).
 Ibid., 306. “…è quella della creatura dal Creatore che, essendo l’essere per essenza, in sè riassume… tutte le altre perfezioni, formalmente se sono perfezioni pure, virtualmente se miste.” (English transl. mine).
 William T. Cavanaugh, “A Joint Declaration? Justification as Theosis in Aquinas and Luther,” The Heythrop Journal, vol. 41, Issue 3, (July 2000), 270.
 Fabro, “Intensive Hermeneutics of Thomistic Philosophy”, 474.
 Ibid., 475.
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, vol. II (Ypsilanti, MI: NovAntiqua, 2009) I, q.75, a.5, ad 4, “…omne participatum comparatur ad participans ut actus eius.”
 Ibidem, “solus Deus, qui est ipsum suum esse, est actus purus et infinitus” (English transl. mine).
 John Rziha, Perfecting Human Actions: St. Thomas Aquinas on Human Participation in Eternal Law (Washington, D.C.: The Catholic University of America Press, 2009), 10.
 Rziha, Perfecting Human Actions: St. Thomas Aquinas on Human Participation in Eternal Law, 10.
 Cf. Aquinas, De Substantiis Separatis, chpt. VIII-IX.
 St. Thomas Aquinas, Comm. super Libros IV Sententiarum, lib.2, d.16, q.1, a.1, ad 3., in Fabro, La Nozione Metafisica di Partecipazione, 306. “…quia Deus dicitur ens hoc modo quod est ipsum suum esse; creatura vero non est ipsum suum esse, sed dicitur ens, quasi esse participans….” (English transl. mine).
 Ibid., 307.
 John F. Wippel, The Metaphysical Thought of Thomas Aquinas: From Finite Being to Uncreated Being (Washington, D.C.: The Catholic University of America Press, 2000), 115.
 Ibidem, 116.
 St Thomas Aquinas, The “Summa Theologica” of St. Thomas Aquinas, pt. III, transl. by Fathers of the English Dominican Province, 2nd ed. (London, England: Burns Oates & Washbourne, 1913), q.4, a.1, ad 2. (Brackets mine.) “…similitudo imaginis attenditur in natura humana secundum quod est capax Dei, scilicet ipsum attingendo propria operatione cognitionis et amoris. Similitudo autem vestigii attenditur solum secundum repraesentationem aliquam ex impressione divina in creatura existentem: non autem ex eo quod creatura irrationalis, in qua est sola talis similitudo, possit ad Deum attingere per solam suam operationem”—Latin text from S. Thomae Aquinatis, Summa Theologiae, vol IV, Tertia Pars, 3rd ed. (Madrid, Spain: Biblioteca de Autores Cristianos, 1964).
 Romanus Cessario, Introduction to Moral Theology, rev. ed. (Washington, D.C.: The Catholic University of America Press, 2001, 2013), 28-29.
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, vol IV, (NovAntiqua, 2010) I-II, q.109, a.3, ad 1. “prout est principium et finis naturalis boni….”
 Ibid., vol. V, (NovAntiqua, 2011) II-II, q.2, a.3, “Sola autem natura rationalis creata habet immediatum ordinem ad Deum. Quia ceterae creaturae non attingunt ad aliquid universale, sed solum ad aliquid particulare participantes divinam bonitatem vel in essendo tantum, sicut inanimata, vel etiam in vivendo et cognoscendo singularia, sicut plantae et animalia, natura autem rationalis, inquantum cognoscit universalem boni et entis rationem, habet immediatum ordinem ad universale essendi principium. Perfectio ergo rationalis creaturae non solum consistit in eo quod ei competit secundum suam naturam, sed etiam in eo quod ei attribuitur ex quadam supernaturali participatione divinae bonitatis.”
 St. Thomas Aquinas, De Veritate, in Quaestiones Disputatae, vol. 1, ed. Fr. Raymundi Spiazzi (Rome, Italy: Marietti, 1949), q.21, a.5, ad 6. “…hoc modo essentia denominator bona sicut et ens; unde, sicut habet esse per participationem, ita et bona est per participationem.” (English transl. mine.)
 St. Thomas Aquinas, Quaestiones Quodlibetales, ed. Fr. Raymundi Spiazzi (Rome, Italy: Marietti, 1949) lib.2, q.2, a.1, resp. (English transl. mine.) “Sic et Deus dicitur bonus essentialiter, quia est ipsa bonitas; creaturae autem dicuntur bonae per participationem, quia habent bonitatem….”
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, I-II, q.110, a.2, ad 2. “…participatio divinae bonitatis quae est gratia….”
 St. Thomas Aquinas, Super Evangelium S. Ioannis, c.I, lect. 4 (http://www.corpusthomisticum.org/cih01.html). “…est duplex participatio divini luminis. Una scilicet perfecta, quae est in gloria, … alia est imperfecta, quae scilicet habetur per fidem, quia venit in testimonium. … Istorum autem modorum prior est modus participationis per fidem; quia per ipsam pervenitur ad speciem.”
 Fabro, La Nozione Metafisica di Partecipazione, 290. “La visione propria e piena avverrà soltanto quando, dopo questa vita, a chi muore in grazia, sarà comunicato il lume della gloria che è, in certo qual modo, la partecipazione più propria della vitalità stessa di Dio, onde la creatura entra in comunione dello stesso oggetto di cui vive Dio stesso. La partecipazione del “lumen gloriae” tende a compiere in modo ineffabile quest’assimilazione dell’intelletto creato….” (English transl. mine).
 St. Thomas Aquinas, Scriptum super Sententiis Magistri Petri Lombardi, vol. III, ed. R. P. Maria Fabianus Moos (Paris, France: P. Lethielleux, 1933), d.19, a.5, q.1, sol.1, p. 602. “Ultima autem participatio suae bonitatis et completissima consistit in visione essentiae ipsius, secundum quam ei convivimus socialiter, quasi amici, cum in ea… beatitudo consistat.” (English transl. mine.)
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, I, q.10, a.1, obj.1, “…interminabilis vitae tota simul et perfecta possessio.” (English transl. mine.)
 Saint Thomas Aquinas, On the Truth of the Catholic Faith: Summa Contra Gentiles, “Book Three: Providence” pt. 1, transl. by Vernon J. Bourke (Garden City, NY: Hanover House, 1956), c.61, no. 2. “…omnia quae per illam videntur, simul et uno intuitu videntur”—Latin text from http://dhspriory.org/thomas/ContraGentiles3a.htm#61.
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, vol. I, I, q.10, a.3, resp.
 Ibid., vol. II, q.93, a.4, resp. “Unde imago Dei tripliciter potest considerari in homine. Uno quidem modo, secundum quod homo habet aptitudinem naturalem ad intelligendum et amandum Deum, et haec aptitudo consistit in ipsa natura mentis, quae est communis omnibus hominibus. Alio modo, secundum quod homo actu vel habitu Deum cognoscit et amat, sed tamen imperfecte, et haec est imago per conformitatem gratiae. Tertio modo, secundum quod homo Deum actu cognoscit et amat perfecte, et sic attenditur imago secundum similitudinem gloriae.”
 Fabro, La Nozione Metafisica di Partecipazione, 294-295.
 St. Thomas Aquinas, Compendium Theologiae, c. 196, http://dhspriory.org/thomas/Compendium.htm#196. “Sed haec quaestio de facili solvitur, si distinguatur inter personam et naturam. Sicut enim in una persona multa sunt membra, ita in una humana natura multae sunt personae, ut participatione speciei multi homines intelligantur quasi unus homo, ut Porphyrius dicit… Per hunc igitur modum defectus originalis iustitiae est peccatum naturae, inquantum derivatur ex inordinata voluntate primi principii in natura humana, scilicet primi parentis, et sic est voluntarium habito respectu ad naturam, voluntate scilicet primi principii naturae, et sic transit in omnes qui ab ipso naturam humanam accipiunt, quasi in quaedam membra ipsius….”
 De Veritate, in Quaestiones Disputatae, q. 29, a.7, sed contra 3, “…Christus et Ecclesia sunt quasi una persona.” (English transl. mine.)
Aquinas, Truth, vol. III, ed. Robert Schmidt, (Indianapolis, IN: Hackett Publishing Co., 1994) q.29, a.7, ad 3. “…unde Christus pro fidelibus tamquam pro suis membris mereri potuit….”—Latin text from De Veritate, in Quaestiones Disputatae.
 Aquinas, The “Summa Theologica” of St. Thomas Aquinas, III, q.48, a.1 resp. “Christo data est gratia non solum sicut singulari personae, sed inquantum est caput Ecclesiae, ut scilicet ab ipso redundaret ad membra. Et ideo opera Christi hoc modo se habent tam ad se quam ad sua membra, sicut se habent opera alterius hominis in gratia constituti ad ipsum”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Fabro, La Nozione Metafisica di Partecipazione, 295. “…la grazia invece degli uomini rigenerati viene participata a traverso il Cristo che l’ha meritata; essa è quindi “gratia Christi”, e tutti i doni che Dio ora effonde nelle anime sante, sono partecipazione della pienezza dei doni che è in lui. Il Cristo va adunque considerato come una nuova fonte di partecipazioni soprannaturali.” (English transl. mine.)
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, I-II, q.112, a.1, resp. “cum nihil aliud sit quam quaedam participation divinae naturae.”
 St. Thomas Aquinas, Commentary on the Gospel of St. John, lect. 5, n. 782, http://dhspriory.org/thomas/John5.htm, “Illud ergo in semetipso vitam habet, quod habet vitam essentialem non participatam, idest quod ipsum est vita. In quolibet autem genere rerum, quod est per essentiam, est causa eorum quae sunt per participationem, sicut ignis est causa omnium ignitorum. Quod ergo est per essentiam vita, est causa et principium omnis vitae in viventibus. Et ideo ad hoc quod aliquod sit principium vitae requiritur quod sit per essentiam vita. Et ideo congrue manifestat dominus se totius vitae principium, dicens se habere vitam in semetipso, idest per essentiam, cum dicit sicut pater habet vitam in semetipso, idest sicut est vivens per essentiam, ita et filius.”
 Summa Theologiae, III, q.7, a.1, ad 1. “…anima Christi non est per suam essentiam divina. Unde oportet quod fiat divina per participationem, quae est secundum gratiam.” (English transl. mine.)
 Ibid., III, q.7, a.1, ad 2., “…oportebat quod attingeret ad Deum per actum fruitionis creatum. Qui quidem esse non potest nisi per gratiam.” (English transl. mine.)
 Fabro, “Intensive Hermeneutics of Thomistic Philosophy”, 481.
 Aquinas, De Veritate, in Quaestiones Disputatae, q. 29, a.5, resp. “…quasi instrumentum divinitatis fuit; et ideo actions eius nobis poterant esse salubres.” (English transl. mine.)
 Aquinas, Summa Theologiae, III, q.19, a.1, resp., “…divina natura utitur operatione naturae humanae sicut operatione sui instrumenti: et similiter humana natura participat operationem divinae naturae, sicut instrumentum participat operationem principalis agentis.” (English transl. mine.)
 Ibid., III, q.8, a.5, resp. “…in anima Christi recepta est gratia secundum maximum eminentiam. Et ideo ex eminentia gratiae quam accepit, competit sibi quod gratia illa ad alios derivetur. Quod pertinet ad rationem capitis.” (English transl. mine.)
 Cf. Fabro, La Nozione Metafisica di Participazione, 296.
 Aquinas, The “Summa Theologica” of St. Thomas Aquinas, III, q.23, a.4, resp., “…filiatio adoptionis est participata similitude filiationis naturalis”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Ibid., III, q.26, a.2, resp. “…competit ei coniungere homines Deo, praecepta et dona homines exhibendo, et pro hominibus ad Deum satisfaciendo et interpellando”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, I-II, q.112, a.1, ad 2. “…sicut in ipsa persona Christi humanitas causat salute nostrum per gratiam, virtute divina principaliter operante; ita etiam in sacramentis novae legis, quae derivantur a Christo, causatur gratia instrumentaliter quidem per ipsa sacramenta, sed principaliter per virtutem spiritus sancti in sacramentis operantis….”
 Catechism of the Catholic Church (New York, NY: Doubleday, 199), #1213
 Vincent de Castro Novo supplied responses to unanswered objections in Disputed Question on the Virtues in General, by St. Thomas Aquinas (http://dhspriory.org/thomas/QDdeVirtutibus.htm#2) a.2, ad 21.
 Aquinas, The “Summa Theologica” of St. Thomas Aquinas, III, q.62, a.5, resp. “Principalis autem causa efficiens gratiae est ipse Deus, ad quem comparator humanitas Christi sicut instrumentum coniunctum, sacramentum autem sicut instrumentum separatum. Et ideo oportet quod virtus salutifera derivetur a divinitate Christi per eius humanitatem in ipsa sacramenta”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Ibid., III, q.49, a.5, ad 3. “…Christo baptizato aperti sunt caeli, non propter ipsum Christum, cui semper caelum patuit:sed ad significandum quod caelum aperitur baptizatis baptism Christi, qui habet efficaciam ex passion ipsius.”
 Ibid., III, q.49, a.1, ad 4. “…ut causa quaedam universalis remissionis peccatorum…”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Ibidem. “Hoc autem fit per baptismum et poenitentiam et alia sacramenta, quae habent virtutem ex passione Christi….”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Matthew Levering, Christ’s Fulfillment of Torah and Temple: Salvation according to Thomas Aquinas, (Notre Dame, IN: University of Notre Dame Press, 2002) 124.
 Council of Trent, Decree on Justification, as found in Heinrich Denzinger, 43rd ed., ed. Peter Hunermann, (San Francisco: Ignatius Press, 2012) #1529, “…qui…sua sanctissima passione in ligno crucis nobis iustificationem meruit [can. 10], et pro nobis Deo Patri satisfecit….”
 Levering, Christ’s Fulfillment of Torah and Temple: Salvation according to Thomas Aquinas, 120.
 Ibidem, “…et non modo reputamur, sed vere iusti nominamur et sumus [cf. 1 Io 3:1], iustitiam in nobis recipientes unusquisque suam, secundum mensuram, quam Spiritus Sanctus partitur singulis prout vult [cf. 1 Cor 12:11], et secundum propriam cuiusque dispositionem et cooperationem.”
 The Holy Bible, Revised Standard Version, 2nd Catholic ed., (San Francisco, CA: Ignatius Press, 2006), 2Pt 1:4. Italics added. Cited by Aquinas in the Summa Theologica, III, q.62, a.1, resp.
 Aquinas, The “Summa Theologica” of St. Thomas Aquinas, III, q.49, a.5, resp. “…sed etiam a peccatis propriis singulorum qui communicant eius passioni per fidem et caritatem et fidem sacramenta”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Cf. Aquinas, The Summa Theologiae of Saint Thomas Aquinas, vol IV, I-II, q.114, a.4, resp., Whether Grace is the Principle of Merit through Charity. Here Aquinas explains that “merit chiefly rest[s] with charity,” both on the part of the Divine ordination and on the part of man’s free-will. He states, “For we must bear in mind that everlasting life consists in the enjoyment of God. Now the human mind’s movement to the fruition of the Divine good is the proper act of charity, whereby all the acts of the other virtues are ordained to this end, since all the other virtues are commanded by charity. Hence the merit of life everlasting pertains first to charity, and secondly, to the other virtues, inasmuch as their acts are commanded by charity. So, likewise, is it manifest that what we do out of love we do most willingly. Hence, even inasmuch as merit depends on voluntariness, merit is chiefly attributed to charity.” In the Latin, “Primo enim considerandum est quod vita aeterna in Dei fruitione consistit. Motus autem humanae mentis ad fruitionem divini boni, est proprius actus caritatis, per quem omnes actus aliarum virtutum ordinantur in hunc finem, secundum quod aliae virtutes imperantur a caritate. Et ideo meritum vitae aeternae primo pertinet ad caritatem, ad alias autem virtutes secundario, secundum quod eorum actus a caritate imperantur. Similiter etiam manifestum est quod id quod ex amore facimus, maxime voluntarie facimus. Unde etiam secundum quod ad rationem meriti requiritur quod sit voluntarium, principaliter meritum caritati attribuitur.”
 Aquinas, The Summa Theologiae of Saint Thomas Aquinas, vol. V, II-II, q.23, a.2, ad 1. “Unde sicut dicimur boni bonitate quae Deus est, et sapientes sapientia quae Deus est, quia bonitas qua formaliter boni sumus est participatio quaedam divinae bonitatis, et sapientia qua formaliter sapientes sumus est participatio quaedam divinae sapientiae; ita etiam caritas qua formaliter diligimus proximum est quaedam participatio divinae caritatis.”
 Cf. 1Jn 4:8.
 Aquinas, The “Summa Theologica” of St. Thomas Aquinas, III, q.73, a.3, ad 3. “…baptismus est sacramentum mortis et passionis Christi prout homo regenerator in Christo virtute passionis eius. Sed Eucharistia est sacramentum passionis Christi prout homo perficitur in unione ad Christum passum. Unde, sicut Baptismus dicitur sacramentum fidei, quae est fundamentum spiritualis vitae; ita Eucharistia dicitur sacramentum caritatis, quae est vinculum perfectionis….”—Latin text from S. Thomae Aquinatis, Summa Theologiae.
 Cf. Pope St. John Paul II, Ecclesia de Eucharistia, dated April 17, 2003, #18-19. In #18, the Holy Father explains, “The Eucharist is a straining toward the goal, a foretaste of the fullness of joy promised by Christ (cf. Jn 15:11); it is in some way the anticipation of heaven, ‘the pledge of future glory.’” Then in #19, he says, “…in celebrating the sacrifice of the Lamb, we are united to the ‘heavenly liturgy’ and become part of that great multitude….The Eucharist is truly a glimpse of heaven appearing on earth” (Boston, MA: Pauline Books & Media, 2003).
 Aquinas, Summa Theologiae, III, q.83, a.1, resp. “…imago est quaedam repraesentativa passionis Christi, quae est vera immolatio.” (English transl. mine.)
 Ibid., “…quantum ad effectum passionis: quia scilicet per hoc sacramentum participes efficimur fructus Dominicae passionis.” (English transl. mine.)
 Aquinas, The “Summa Theologica” of St. Thomas Aquinas, III, q.79, a.7, resp. “…Sic igitur hoc sacramentum sumentibus quidem prodest per modum sacramenti et per modum sacrificii, quia pro omnibus sumentibus offertur: dicitur enim in canone Missae: Quotquot ex hac altaris participatione sacrosanctum corpus et sanguinem filii tui sumpserimus, omni benedictione caelesti et gratia repleamur”—Latin text from S. Thomae Aquinatis, Summa Theologiae.