When did Christ reach the "age of reason"?

Femina circumdabit virum.

How long wilt thou be dissolute in deliciousness, O wandering daughter? for the Lord hath created a new thing upon the earth: A WOMAN SHALL COMPASS A MAN. (Jeremiah 31:22)

St. Thomas Aquinas, following the tradition of the Fathers (especially St. Jerome) reads this verse from Jeremiah as a prophetic sign that the Christ Child, from the first moment of his conception and while yet enclosed within the womb of the Woman Mary, will be a “perfect man” – which means that he will have perfect use of both reason and will.

Though, in general, by the “age of reason” we refer to around six or seven years of age, the real meaning of the phrase is to specify the point in which a child attains to the use of reason and free-will. When a child is capable of making morally significant decisions, we say that he has reached the “age of reason”.

Some will be quite surprised to realize that the Church has taught, in her ordinary Magisterium, that Christ our Savior had use of reason from the very first moment of his conception. While yet in the womb, our Lord was a rational man in regard to the powers of his human intellect, though his body was yet that of a tiny child.

Magisterial texts

I have already written several articles regarding the doctrine of Christ’s universal and unlimited knowledge with regard to all created things, past, present and future [n.b. his knowledge was not absolutely unlimited, but was unlimited in relation to created realities]. The Church teaches that Jesus knew all things (even the hour of his Second Coming) while he was on earth, in his human intellect. Read the article [here – Why Jesus had to know all things] or another one [here – Jesus knew the day and the hour] (and, see [here] for why Jesus didn’t tell us the day and hour of the Last Judgment).

In these previous articles you will see numerous papal documents which affirm that Jesus knew all created things, and you can consider something of why it is so important for us to hold that Jesus did know all things in his humanity.

Here, I will simply reproduce two very clear magisterial quotes which affirm that Jesus knew all things from the first moment of his conception, even while he was yet in the womb.

The following proposition is rejected: “The opinion cannot be declared certain, which holds that the soul of Christ was ignorant of nothing but from the beginning knew in the Word everything, past, present and future, that is to say everything which God knows with the ‘knowledge of vision’.” (Pope Benedict XV, Decree of the Holy Office of 1918)

“The knowledge and love of our Divine Redeemer, of which we were the object from the first moment of His Incarnation, exceed all the human intellect can hope to grasp. For hardly was He conceived in the womb of the Mother of God, when He began to enjoy the beatific vision, and in that vision all the members of His Mystical Body were continually and unceasingly present to Him, and He embraced them with His redeeming love.” (Pius XII, Mystici Corporis 75)

The Church has taught that, even in his human intellect and soul, Christ Jesus knew – with an unlimited, universal, and infallible knowledge – all things, past, present and future. Further, the popes do not say that this knowledge came little by little or that there was any time in which he was ignorant – rather, it is affirmed that our Savior possessed this knowledge from the first moment of his conception.

The Christ Child, living in the womb of Mary his Mother, already had perfect use of reason and will – he was able to know each of us, and he loved us all not only as God but even as man. The unborn Child yet had a Sacred Heart with which he loved us even in his humanity.

The teaching of St. Thomas Aquinas, the defender of Christ’s human knowledge

Now, we do believe that Jesus grew in knowledge, but this refers only to his acquired knowledge (gained through sense experience). However, our Savior had use of reason not merely through acquired knowledge but also through the beatific vision (for his human was intimately united with the Divine Essence and knew all things through this union, just as the saints in heaven [no, in a manner yet more perfect still]). Further, our Lord had infused knowledge, like the angels.

From the first moment of his conception, Jesus was filled with the Holy Spirit – shall we not affirm that he knew all created things (all that has been, is, and will ever be) through this grace? If the apostles knew many languages through the Spirit, can we doubt that the Infant (from the moment of his conception) knew every language through the gift of tongues? If St. John Vianney could read hearts through the power of the Spirit, shall we doubt that the divine Infant (yet in the womb) knew all that was in the heart of the holy Curé? All grace comes through the humanity of Jesus, thus (in his humanity) he must possess all gifts and all knowledge and all love in a most excellent and perfect degree. None have been more gifted than Jesus – and who would not blush to claim to be more excellent than our Savior, even in his infancy?! The greatest of men is yet nothing compared with this little Baby!

St. Thomas Aquinas shows that the Savior had the use of free-will and had attained to the age of reason in the first moment of his conception – see ST III, q.34, a.2 [here]. The Angelic Doctor makes his proof from the fact that Christ did not grow in spiritual perfection through his life, nor did he progress from an imperfect state to a perfect state. Thus, it is clear that he must have been perfect even in his conception, which requires that he had the use of free-will and reason so as to co-operate perfectly with the fullness of grace which he possessed even in his humanity.

St. Thomas credits St. Augustine as teaching that Christ did not increase in merit through his life (“Increase of merit was absolutely impossible to the soul of Christ” – Paterius, Expos. Vet. et Nov. Test. super Ex. 40) and concludes that this requires that Christ merited all things in the very first moment of his conception. Upon coming into the world, our Savior merited our salvation – but one must be rational in order to merit, therefore it is clear that Christ (in the moment he was conceived) had the use of reason. Even in the womb, the Christ Child made morally significant decisions (indeed, he merited our salvation and his glory), he had already reached the “age of reason”.

Christ increased in knowledge with respect to experiential knowledge gained through the senses. But, of course, our Savior knew all created things through the beatific vision and through the infused knowledge given by the Holy Spirit. There can be no doubt that Jesus, from the first moment of his conception, knew all things that had been or would ever be, and that he had the use of reason. The Infant in the womb is already a “perfect man”, insofar as he has the perfect use of reason and will – he is no irrational child, but the Everlasting Man.

What do we mean when we say that Jesus was rational while in the womb

When we say that Jesus was rational while in the womb, we mean to say that he had perfect use of reason, and his intellect was in no way hindered – he was not ignorant, nor did he slowly come into the age of reason. However, his body was yet tiny and he could not always manifest the rational powers of his intellect – from the first moment of his conception we may well presume that his process of gestation was similar in many respects to ours; thus, our Savior was an embryo for a time and it is likely that his body did not begin with hands and feet, but (like our own) developed while in the womb.

When Jesus was still a small embryo, he was rational and capable of making morally significant decisions (he already knew you, loved you, and was praying for you, in his humanity - as an embryo, he already consecrated the unborn St. John the Baptist), but these rational actions could not be manifested through his body. What seems reasonable to conclude is that, in the same time that ordinary babies are able to act instinctively, Christ was able to manifest the rational powers of his soul. Thus, for example, when an unborn child is able to move around within his mother’s womb, Christ was able to go to and fro as he willed. As an unborn child reaches a point of bodily maturation in which he is able to “kick” and push the enclosure of the womb forcefully enough that his mother can feel it, Christ was able to caress his Mother and express his love for her through gentle rubs. Finally, at the time when an unborn babe develops fingers and is able to suck his thumb, our Savior would have been capable of sign-language (at least, as soon as he had developed the synapses and nerve endings etc. which would allow him to move his fingers at will, he was able to sign).

[To think of this from Mary’s perspective, you may consider our earlier article on what it was like to be pregnant with Jesus, here]

It was Christ’s body which needed to develop, together with his senses; but his rational soul was not limited by his body, for he had knowledge which did not depend on mere sense experience. Thus, even before he had a brain (that is, brain tissue), our Savior was praying for you and for me; even before he had hands and feet, he was accomplishing our salvation; even before the cells of his body had developed into flesh tissue, he made the rational choice to offer his body upon the Cross; even before his body had developed heart tissue, each of us were held in a loving embrace within his Sacred Heart - Wherefore, when he cometh into the world, he saith: Sacrifice and oblation thou wouldest not: but a body thou hast fitted to me. (Hebrews 10:5)

Why this is important

There was never a moment in our Savior’s life when he did not know and love each and every one of us. There was never a moment when he was simply the victim of external events, but he always offered whatever he did and whatever he suffered for our salvation. Even as a child, an infant, an embryo, our Savior loved us (not only as God but in his humanity, with his Sacred Heart).

There is a wonderful prayer which speaks to the Child in the womb of his Mother. This prayer is no mere sentiment, for Jesus was a rational man when he was first conceived – he knew all the prayers we would offer and he received them, and he loved us.

“O Jesus living in Mary, come and live in Thy servants. In the spirit of Thy holiness, in the fullness of Thy might, in the truth of Thy virtues, in the perfection of Thy ways, in the communion of Thy mysteries. Subdue every hostile power, in Thy spirit, for the glory of the Father. Amen.”

The infant Jesus, living in the womb of his Mother, is already our Redeemer and our Lord. Already he knew and loved us. He is no mere child without control of reason, but already he hears our prayers and prays for us – for, by virtue of his union with the divinity, this Child knows all things past, present and future, and his soul is not limited by his tiny and sacred body.

I will not enter into the discussion of the powers of the Christ Child in the early years of his youth – it should be fairly clear that, when growing up, even as a toddler, our Lord was a rational man with perfect use of reason and free-will. Thus, he certainly never had a “tantrum” or a “fit”, he never had to be “taught”, he never made a mistake – though physically a young boy, he already was wise beyond all men.

Still, we must be very clear on this point, Christ did not necessarily act wholly differently from other young children. Rather, it is quite certain, that he chose to hide his glory. Our Savior did not speak foreign languages as a child (though he could have), nor did he solve problems of calculus or discuss the future (though, again, he could have). Indeed, it is most likely that our Lord (until the time of his public ministry) generally chose to manifest only what he knew from acquired knowledge gained through sense experience, which would be age-appropriate [a certain exception to this could be his quasi-public teaching in the Temple at the age of twelve]. Thus, as a three-year-old, he would have acted in many ways like a three-year-old (like a perfect three-year-old).

You have professed this doctrine yourself, though you may not have noticed!

Lest you think all this is far beyond what you can accept. Lest you should believe that this is unbelievable. I would point out that – if you are a native English-speaker – I am certain that you have already asserted many times (and in public) that the Child Jesus reached the age of reason when yet an infant. For you have certainly sung the popular Christmas carol “What Child is this?” by William Chatterton Dix (ca. 1865). In that carol, we hear the following:

 “Why lies He in such mean estate / Where ox and ass are feeding? / Good Christian, fear: for sinners here, / The silent Word is pleading.”

The carol sings that the newborn Babe is “pleading”, that is “praying” for us poor sinners. How can an infant pray, if he is not yet rational? How can a child plead – that is “plead” in such a way as to truly merit our salvation – if he has no free-will? Indeed, the Christ Child was already praying for us when laid in the manger, and so too he was praying for us from the first moment of his conception.

This is why we must hold that Jesus had the use of reason from the first instant of the Incarnation: There was never a moment when our Savior was irrational, never a moment when he did not know us and love us, never a moment when he was simply a passive observer; but all along, from the beginning to the end, our Lord knew and loved each of us, he merited our salvation, and he prayed in our behalf.

This is no “hard teaching”, but a wonderful proclamation of the love of our Savior. How consoling it is to look upon the Christ Child and know that he already understands me, knows me, and loves me!