78. The Incarnation: Matter, Genealogy, and Original Sin

Summary

This lecture examines fundamental questions about the Incarnation, particularly whether Christ’s flesh was taken from the human race through Adam and how his conception relates to original sin. Berquist explores the genealogies of Christ in Matthew and Luke, the material composition of Christ’s body from the Virgin’s blood, and how Christ can be said to be “in” the patriarchs without contracting original sin. The discussion demonstrates how Christ assumed human nature while remaining free from sin and corruption.

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Lecture Notes

Main Topics #

Christ’s Flesh and the Human Race #

Whether Christ’s body was taken from Adam and descended through the patriarchs
The distinction between Christ being “in” the fathers materially versus generatively
How Christ can be truly human and related to humanity without contracting original sin
The role of the Holy Spirit as the efficient cause versus the material cause of conception

The Virgin Mary’s Integrity #

Whether providing matter for Christ’s body would diminish or corrupt the Virgin
The distinction between actual bodily parts (flesh and bones) and potential matter (blood)
How blood, though part of the body’s nourishment, is flesh in potency rather than in act
The preservation of the Virgin’s bodily wholeness despite providing material for Christ’s conception

Purity and Concupiscence #

Whether Christ’s flesh was formed from pure blood as opposed to menstrual blood
How the matter in Christ’s conception differs from conception in other men
The role of lustful desire (concupiscence) in ordinary human generation
How the Holy Spirit purified the Virgin’s blood, removing all association with concupiscence

Original Sin and the Fathers #

Whether Christ’s flesh, insofar as it was in Adam and other fathers, was infected with sin
The distinction between two possible errors: attributing the fathers’ sinfulness to Christ, or attributing Christ’s sinlessness to the fathers
How Christ was not subject to sin according to the condition he had in the fathers
The meaning of “the whole flesh of the ancient fathers was subject to sin”

Key Arguments #

On Material vs. Generative Presence in Adam #

Question: If Christ’s flesh was in Adam and the patriarchs, was it not subject to sin like theirs?
Thomas’s Response: Christ was in Adam according to bodily substance (material cause) but not according to ratio seminalis (seed-like generative principle). Original sin is contracted through the seed-like reason, not through the matter itself. Therefore, Christ’s flesh, though materially descended from Adam, was not subject to the law of sin transmission.
Key Distinction: “The fathers were subject to sin. But Christ was altogether immune from sin altogether.”

On the Virgin’s Blood as Matter #

Objection: Christ’s body should be formed from flesh and bones (actual parts of the mother), not blood, since flesh differs from blood.
Response: Blood is flesh in potency—the matter from which flesh is formed through natural digestion. The Virgin’s actual flesh and bones are integral parts of her body and cannot be taken without corruption. Blood, being the nourishment distributed throughout the body, can provide matter without diminishing her bodily integrity.
Significance: This preserves both the true humanity of Christ’s body and the Virgin’s corporeal wholeness.

On Concupiscence and Purity #

Distinction: In ordinary human conception, the menstrual blood that serves as matter is drawn to the place of generation through lustful desire, thereby carrying the impurity of concupiscence.
Christ’s Conception: The Holy Spirit directly formed Christ’s body from the Virgin’s pure blood without any concupiscence, thus the body was formed from blood that was “most chaste and most purified.”
Result: “The body of Christ was not from the imperfect seed of the woman, even though it has something of the nature of seed.”

On Errors to Avoid #

First Error: Attributing to Christ or his flesh the condition of the fathers (e.g., saying Christ sinned in Adam because somehow he was “in” Adam). This is false because Christ was not derived from Adam according to the seed-like reason through which sin is transmitted.
Second Error: Attributing to the flesh as it was in the fathers the condition of Christ (e.g., saying that because Christ’s flesh was sinless, there must have been some pure, uninfected part of the fathers from which it came). This is also false because all human flesh from conception through concupiscence is infected with the condition of sin.

Important Definitions #

Bodily Substance (corporalis substantia) #

The material matter of a body as distinct from its active generative principle. Christ’s flesh was in Adam according to bodily substance—the material would eventually come to form his body through the line of descent—but not according to the seed-like reason.

Seed-like Reason (ratio seminalis) #

The active generative principle in reproduction through which offspring are produced and inherit characteristics (including the subjection to sin) from their parents. Christ was not in the fathers according to this principle because the Holy Spirit, not a human seed, was the efficient cause of his conception.

Flesh in Potency (caro in potentia) #

Matter that has the potential to become flesh through proper digestion and formation, as opposed to flesh in act (caro in actu), which is already formed flesh. Blood is flesh in potency; it can be formed into actual flesh but is not itself actual flesh.

Concupiscence (concupiscentia) #

Disordered desire, particularly sexual desire. In the context of conception, it refers to the lustful desire accompanying ordinary human generation. Christ’s conception was explicitly free from concupiscence.

Examples & Illustrations #

The Ray of the Sun #

Augustine’s analogy: just as a ray of sun can dry the filthy members of the earth without being stained by them, so the “splendor of eternal light” (God’s divinity) can form a body from matter that comes from a sinful lineage without being polluted. The eternal light itself remains uncorrupted even as it radiates through base matter.

The Levirate Marriage Problem #

Berquist briefly addresses the problem of Joseph’s genealogy in Matthew and Luke: Joseph appears to have two fathers (Jacob in Matthew, Heli in Luke). This could be resolved through the Jewish custom of levirate marriage, where a man could be the natural son of one father and the legal son of another.

The Integrity of the Body #

The Virgin’s body is like a unified organism: her flesh and bones are actual integral parts that cannot be removed without corruption. But blood, being the nourishment distributed to all parts, can provide matter for a new body without diminishing her own integrity—analogous to how nourishment sustains a body without depleting it.

Notable Quotes #

“But lest the feminine sex be despised, it was fitting that he took on flesh… The son of God was born from one.” — Augustine, cited approvingly by Berquist

“The Catholic faith… the same son of God… was included or contained in the womb of the mother, as if he was not outside there… as if he had given up the administration of heaven and earth.” — Augustine, Against Faustus, addressing the Manichaean objection

“The flesh of Christ was not according to some individually signed matter in Adam… According to the condition of the fathers… flesh was subject to sin. According to the condition of Christ… the flesh was not infected with sin.” — Thomas Aquinas

“The whole flesh of the ancient fathers was subject to sin… [but] in it nothing immune from sin from which afterwards the body of Christ could be formed.” — Thomas Aquinas

Questions Addressed #

Q: How can Christ be descended from Adam without contracting original sin? #

Answer: Christ was in Adam according to bodily substance (material composition) but not according to the seed-like reason (the active generative principle through which sin is transmitted). Original sin passes through the generative power of human seed; it does not inhere in matter itself. Since the Holy Spirit, not human generation, formed Christ’s body, he was free from sin despite his material descent from Adam.

Q: How could the Virgin’s body remain intact if Christ’s body was formed from her? #

Answer: The matter came from her blood, not from her actual flesh and bones. Blood is flesh in potency—it is the nourishment that sustains the body and from which flesh is formed—but it is not yet actual flesh. Therefore, the Virgin’s actual bodily parts (flesh and bones) were not diminished, and her corporal integrity was preserved without detriment.

Q: Was Christ’s flesh formed from pure blood or menstrual blood? #

Answer: In Christ’s case, the blood was purified of all association with concupiscence. In ordinary human conception, menstrual blood carries the impurity of lustful desire through which it is drawn to the place of generation. In Christ’s conception, the Holy Spirit directly formed the body from the Virgin’s pure blood without any involvement of human concupiscence, making it “most chaste and most purified” blood.

Q: If Christ’s flesh was in the fathers, was it not subject to sin like theirs? #

Answer: There is an important distinction: flesh as it was in the fathers (under the condition of generation through concupiscence and the seed-like reason) was subject to sin. But flesh as it was in Christ (formed by the Holy Spirit without concupiscence or seed-like generation) was free from sin. The flesh itself did not change; rather, the condition in which it existed was radically different.