QUESTION 33: OF THE MODE AND ORDER OF CHRIST'S CONCEPTION
We have now to consider the mode and order of Christ's conception,
concerning which there are four points of inquiry:
(1) Whether Christ's body was formed in the first instant of its
(2) Whether it was animated in the first instant of its conception?
(3) Whether it was assumed by the Word in the first instant of its
(4) Whether this conception was natural or miraculous?
Article 1: Whether Christ's body was formed in the first instant of its conception?
Objection 1: It would seem that Christ's body was not formed in the first
instant of its conception. For it is written (Jn. 2:20): "Six-and-forty
years was this Temple in building"; on which words Augustine comments as
follows (De Trin. iv): "This number applies manifestly to the perfection
of our Lord's body." He says, further (Questions. lxxxiii, qu. 56): "It is not
without reason that the Temple, which was a type of His body, is said to
have been forty-six years in building: so that as many years as it took
to build the Temple, in so many days was our Lord's body perfected."
Therefore Christ's body was not perfectly formed in the first instant of
Objection 2: Further, there was need of local movement for the formation of Christ's body in order that the purest blood of the Virgin's body might be brought where generation might aptly take place. Now, no body can be moved locally in an instant: since the time taken in movement is divided according to the division of the thing moved, as is proved Phys. vi. Therefore Christ's body was not formed in an instant.
Objection 3: Further, Christ's body was formed of the purest blood of the
Virgin, as stated above (Question , Article ). But that matter could not be in
the same instant both blood and flesh, because thus matter would have
been at the same time the subject of two forms. Therefore the last
instant in which it was blood was distinct from the first instant in
which it was flesh. But between any two instants there is an interval of
time. Therefore Christ's body was not formed in an instant, but during a
space of time.
Objection 4: Further, as the augmentative power requires a fixed time for its
act, so also does the generative power: for both are natural powers
belonging to the vegetative soul. But Christ's body took a fixed time to
grow, like the bodies of other men: for it is written (Lk. 2:52) that He
"advanced in wisdom and age." Therefore it seems for the same reason that
the formation of His body, since that, too, belongs to the generative
power, was not instantaneous, but took a fixed time, like the bodies of
On the contrary, Gregory says (Moral. xviii): "As soon as the angel
announced it, as soon as the Spirit came down, the Word was in the womb,
within the womb the Word was made flesh."
I answer that, In the conception of Christ's body three points may be
considered: first, the local movement of the blood to the place of
generation; secondly, the formation of the body from that matter;
thirdly, the development whereby it was brought to perfection of
quantity. of these, the second is the conception itself; the first is a
preamble; the third, a result of the conception.
Now, the first could not be instantaneous: since this would be contrary
to the very nature of the local movement of any body whatever, the parts
of which come into a place successively. The third also requires a
succession of time: both because there is no increase without local
movement, and because increase is effected by the power of the soul
already informing the body, the operation of which power is subject to
But the body's very formation, in which conception principally consists,
was instantaneous, for two reasons. First, because of the infinite power
of the agent, viz. the Holy Ghost, by whom Christ's body was formed, as
stated above (Question , Article ). For the greater the power of an agent, the
more quickly can it dispose matter; and, consequently, an agent of
infinite power can dispose matter instantaneously to its due form.
Secondly, on the part of the Person of the Son, whose body was being
formed. For it was unbecoming that He should take to Himself a body as
yet unformed. While, if the conception had been going on for any time
before the perfect formation of the body, the whole conception could not
be attributed to the Son of God, since it is not attributed to Him except
by reason of the assumption of that body. Therefore in the first instant
in which the various parts of the matter were united together in the
place of generation, Christ's body was both perfectly formed and
assumed. And thus is the Son of God said to have been conceived; nor
could it be said otherwise.
Reply to Objection 1: Neither quotation from Augustine refers to formation alone
of Christ's body, but to its formation, together with a fixed development
up to the time of His birth. Wherefore in the aforesaid number are
foreshadowed the number of months during which Christ was in the Virgin's
Reply to Objection 2: This local movement is not comprised within the conception
itself, but is a preamble thereto.
Reply to Objection 3: It is not possible to fix the last instant in which that
matter was blood: but it is possible to fix the last period of time which
continued without any interval up to the first instant in which Christ's
body was formed. And this instant was the terminus of the time occupied
by the local movement of the matter towards the place of generation.
Reply to Objection 4: Increase is caused by the augmentative power of that which
is the subject of increase: but the formation of the body is caused by
the generative power, not of that which is generated, but of the father
generating from seed, in which the formative power derived from the
father's soul has its operation. But Christ's body was not formed by the
seed of man, as stated above (Question , Article , ad 3), but by the operation of
the Holy Ghost. Therefore the formation thereof should be such as to be
worthy of the Holy Ghost. But the development of Christ's body was the
effect of the augmentative power in Christ's soul: and since this was of
the same species as ours, it behooved His body to develop in the same way
as the bodies of other men, so as to prove the reality of His human
Article 2: Whether Christ's body was animated in the first instant of its conception?
Objection 1: It would seem that Christ's body was not animated in the first
instant of its conception. For Pope Leo says (Ep. ad Julian.): "Christ's
flesh was not of another nature than ours: nor was the beginning of His
animation different from that of other men." But the soul is not infused
into other men at the first instant of their conception. Therefore
neither should Christ's soul have been infused into His body in the first
instant of its conception.
Objection 2: Further, the soul, like any natural form, requires determinate
quantity in its matter. But in the first instant of its conception
Christ's body was not of the same quantity as the bodies of other men
when they are animated: otherwise, if afterwards its development had been
continuous, either its birth would have occurred sooner, or at the time
of birth He would have been a bigger child than others. The former
alternative is contrary to what Augustine says (De Trin. iv), where he
proves that Christ was in the Virgin's womb for the space of nine
months: while the latter is contrary to what Pope Leo says (Serm. iv in
Epiph.): "They found the child Jesus nowise differing from the generality
of infants." Therefore Christ's body was not animated in the first
instant of its conception.
Objection 3: Further, whenever there is "before" and "after" there must be
several instants. But according to the Philosopher (De Gener. Animal. ii)
in the generation of a man there must needs be "before" and "after": for
he is first of all a living thing, and afterwards, an animal, and after
that, a man. Therefore the animation of Christ could not be effected in
the first instant of His conception.
On the contrary, Damascene says (De Fide Orth. iii): "At the very
instant that there was flesh, it was the flesh of the Word of God, it was
flesh animated with a rational and intellectual soul."
I answer that, For the conception to be attributed to the very Son of
God, as we confess in the Creed, when we say, "who was conceived by the
Holy Ghost," we must needs say that the body itself, in being conceived,
was assumed by the Word of God. Now it has been shown above (Question , Articles ,2) that the Word of God assumed the body by means of the soul, and the
soul by means of the spirit, i.e. the intellect. Wherefore in the first
instant of its conception Christ's body must needs have been animated by
the rational soul.
Reply to Objection 1: The beginning of the infusion of the soul may be considered
in two ways. First, in regard to the disposition of the body. And thus,
the beginning of the infusion of the soul into Christ's body was the same
as in other men's bodies: for just as the soul is infused into another
man's body as soon as it is formed, so was it with Christ. Secondly, this
beginning may be considered merely in regard to time. And thus, because
Christ's body was perfectly formed in a shorter space of time, so after a
shorter space of time was it animated.
Reply to Objection 2: The soul requires due quantity in the matter into which it
is infused: but this quantity allows of a certain latitude because it is
not fixed to a certain amount. Now the quantity that a body has when the
soul is first infused into it is in proportion to the perfect quantity to
which it will attain by development: that is to say, men of greater
stature have greater bodies at the time of first animation. But Christ at
the perfect age was of becoming and middle stature: in proportion to
which was the quantity of His body at the time when other men's bodies
are animated; though it was less than theirs at the first instant of His
conception. Nevertheless that quantity was not too small to safeguard the
nature of an animated body; since it would have sufficed for the
animation of a small man's body.
Reply to Objection 3: What the Philosopher says is true in the generation of
other men, because the body is successively formed and disposed for the
soul: whence, first, as being imperfectly disposed, it receives an
imperfect soul; and afterwards, when it is perfectly disposed, it
receives a perfect soul. But Christ's body, on account of the infinite
power of the agent, was perfectly disposed instantaneously. Wherefore, at
once and in the first instant it received a perfect form, that is, the
Article 3: Whether Christ's flesh was first of all conceived and afterwards assumed?
Objection 1: It would seem that Christ's flesh was first of all conceived, and
afterwards assumed. Because what is not cannot be assumed. But Christ's
flesh began to exist when it was conceived. Therefore it seems that it
was assumed by the Word of God after it was conceived.
Objection 2: Further, Christ's flesh was assumed by the Word of God, by means
of the rational soul. But it received the rational soul at the term of
the conception. Therefore it was assumed at the term of the conception.
But at the term of the conception it was already conceived. Therefore it
was first of all conceived and afterwards assumed.
Objection 3: Further, in everything generated, that which is imperfect
precedes in time that which is perfect: which is made clear by the
Philosopher (Metaph. ix). But Christ's body is something generated.
Therefore it did not attain to its ultimate perfection, which consisted
in the union with the Word of God, at the first instant of its
conception; but, first of all, the flesh was conceived and afterwards
On the contrary, Augustine says (De Fide ad Petrum xviii [*Written by
Fulgentius]): "Hold steadfastly, and doubt not for a moment that Christ's
flesh was not conceived in the Virgin's womb, before being assumed by the
I answer that, As stated above, we may say properly that "God was made
man," but not that "man was made God": because God took to Himself that
which belongs to man---and that which belongs to man did not pre-exist,
as subsisting in itself, before being assumed by the Word. But if
Christ's flesh had been conceived before being assumed by the Word, it
would have had at some time an hypostasis other than that of the Word of
God. And this is against the very nature of the Incarnation, which we
hold to consist in this, that the Word of God was united to human nature
and to all its parts in the unity of hypostasis: nor was it becoming that
the Word of God should, by assuming human nature, destroy a pre-existing
hypostasis of human nature or of any part thereof. It is consequently
contrary to faith to assert that Christ's flesh was first of all
conceived and afterwards assumed by the Word of God.
Reply to Objection 1: If Christ's flesh had been formed or conceived, not
instantaneously, but successively, one of two things would follow:
either that what was assumed was not yet flesh, or that the flesh was
conceived before it was assumed. But since we hold that the conception
was effected instantaneously, it follows that in that flesh the beginning
and the completion of its conception were in the same instant. So that,
as Augustine [*Fulgentius, De Fide ad Petrum xviii] says: "We say that
the very Word of God was conceived in taking flesh, and that His very
flesh was conceived by the Word taking flesh."
From the above the reply to the Second Objection is clear. For in the
same moment that this flesh began to be conceived, its conception and
animation were completed.
Reply to Objection 3: The mystery of the Incarnation is not to be looked upon as
an ascent, as it were, of a man already existing and mounting up to the
dignity of the Union: as the heretic Photinus maintained. Rather is it to
be considered as a descent, by reason of the perfect Word of God taking
unto Himself the imperfection of our nature; according to Jn. 6:38: "I
came down from heaven."
Article 4: Whether Christ's conception was natural?
Objection 1: It would seem that Christ's conception was natural. For Christ is
called the Son of Man by reason of His conception in the flesh. But He is
a true and natural Son of Man: as also is He the true and natural Son of
God. Therefore His conception was natural.
Objection 2: Further, no creature can be the cause of a miraculous effect. But
Christ's conception is attributed to the Blessed Virgin, who is a mere
creature: for we say that the Virgin conceived Christ. Therefore it seems
that His conception was not miraculous, but natural.
Objection 3: Further, for a transformation to be natural, it is enough that
the passive principle be natural, as stated above (Question , Article ). But in
Christ's conception the passive principle on the part of His Mother was
natural, as we have shown (Question , Article ). Therefore Christ's conception
On the contrary, Dionysius says (Ep. ad Caium Monach.): "Christ does in
a superhuman way those things that pertain to man: this is shown in the
miraculous virginal conception."
I answer that, As Ambrose says (De Incarn. vi): "In this mystery thou
shalt find many things that are natural, and many that are supernatural."
For if we consider in this conception anything connected with the matter
thereof, which was supplied by the mother, it was in all such things
natural. But if we consider it on the part of the active power, thus it
was entirely miraculous. And since judgment of a thing should be
pronounced in respect of its form rather than of its matter: and likewise
in respect of its activity rather than of its passiveness: therefore is
it that Christ's conception should be described simply as miraculous and
supernatural, although in a certain respect it was natural.
Reply to Objection 1: Christ is said to be a natural Son of Man, by reason of His
having a true human nature, through which He is a Son of Man, although He
had it miraculously; thus, too, the blind man to whom sight has been
restored sees naturally by sight miraculously received.
Reply to Objection 2: The conception is attributed to the Blessed Virgin, not as
the active principle thereof, but because she supplied the matter, and
because the conception took place in her womb.
Reply to Objection 3: A natural passive principle suffices for a transformation
to be natural, when it is moved by its proper active principle in a
natural and wonted way. But this is not so in the case in point.
Therefore this conception cannot be called simply natural.