Thomas Aquinas Commentary John 8:12-20

"Again therefore Jesus spake unto them, saying, I am the light of the world: he that followeth me shall not walk in the darkness, but shall have the light of life. The Pharisees therefore said unto him, Thou bearest witness of thyself; thy witness is not true. Jesus answered and said unto them, Even if I bear witness of myself, my witness is true; for I know whence I came, and whither I go; but ye know not whence I come, or whither I go. Ye judge after the flesh; I judge no man. Yea and if I judge, my judgment is true; for I am not alone, but I and the Father that sent me. Yea and in your law it is written, that the witness of two men is true. I am he that beareth witness of myself, and the Father that sent me beareth witness of me. They said therefore unto him, Where is thy Father? Jesus answered, Ye know neither me, nor my Father: if ye knew me, ye would know my Father also. These words spake he in the treasury, as he taught in the temple: and no man took him; because his hour was not yet come." — John 8:12-20 (ASV)

1. The Evangelist has presented Christ as teaching; now he shows two things. First, he shows the power this teaching has to give light. Second, he shows what Christ himself said about it, beginning with the Pharisees’ objection: you give testimony about yourself.

   With respect to the first point, the Evangelist does three things. First, he states Christ’s prerogative concerning spiritual light. Second, he shows the effect of this prerogative: he who follows me does not walk in darkness. Third, he reveals its fruit: but will have the light of life.

2. Regarding Christ’s prerogative as the spiritual light, the Evangelist says, Jesus spoke to them again, saying: I am the light of the world. We can connect this statement to what came before. Christ had just forgiven the woman’s sin, saying, neither will I condemn you (John 8:11). So that they would have no doubt that He could forgive sins, He chose to show the power of His divinity more openly by declaring that He is the light that drives away the darkness of sin.

   Alternatively, we can connect this statement with what the Pharisees said earlier: search the Scriptures and see that, out of Galilee, a prophet does not rise (John 7:52). Because they thought of Him as a Galilean, linked to a specific place, they rejected His teaching. In response, our Lord shows them that He is the universal light of the entire world, saying, I am the light of the world—not just of Galilee, or of Palestine, or of Judea.

3. As Augustine relates, the Manicheans misunderstood this. Because they judged by their imagination, which cannot rise to intellectual and spiritual realities, they believed that only bodies existed. Thus, they said that God was a body and a kind of infinite light. They further thought that the sun we see with our physical eyes was Christ the Lord, and that this is why Christ said, I am the light of the world.

   However, this opinion is untenable, and the Catholic Church rejects such a fiction. The physical sun is a light that can be perceived by the senses. Consequently, it is not the highest light, which the intellect alone grasps. This higher light is the intelligible light characteristic of the rational creature, and it is this light Christ speaks of here: I am the light of the world. As we read earlier: he was the true light, which enlightens every man coming into this world (John 1:9).

   Perceptible light is an image of spiritual light. Every sensible thing is particular, whereas intellectual things are a kind of whole. Just as physical light affects both the thing seen (by making colors visible) and the one seeing (by conditioning the eye for sight), so intellectual light enables the intellect to know. This is because all light in a rational creature is derived from that supreme light which enlightens every man coming into the world.

   Furthermore, this supreme light makes all things intelligible, since all forms—which give things the capacity to be known—are derived from it, just as the forms of artifacts are derived from the art and reason of the artisan. As it is written, how magnificent are your works, O Lord! You have made all things in wisdom (Psalms 103:24). Thus, Christ truly says, I am the light of the world; He is not the sun that was made, but the One who made the sun. Yet as Augustine says, the light who made the sun was Himself made under the sun and covered with a cloud of flesh, not to be hidden but to be moderated.

4. This also eliminates the heresy of Nestorius, who said that the Son of God was united to human nature by a mere indwelling.

   For it is obvious that the one who said, I am the light of the world, was a human being. Therefore, unless the one who spoke and appeared as a human being was also the person of the Son of God, he could not have said, I am the light of the world, but rather, "the light of the world dwells in me."

5. The effect of this light is to expel darkness, and so He says, he who follows me does not walk in darkness. Because this light is universal, it universally expels all darkness.

   Now, there are three kinds of darkness. First is the darkness of ignorance: they have neither known nor understood; they walk in darkness (Psalms 81:5). This is the darkness of reason in itself, insofar as it is darkened by its own limitations. Second is the darkness of sin: you were at one time darkness, but now you are light in the Lord (Ephesians 5:8). This darkness belongs to human reason not from itself, but from affections that, being badly disposed by passion or habit, seek something as good that is not truly good. Third is the darkness of eternal damnation: cast the unprofitable servant into the exterior darkness (Matthew 25:30).

   The first two kinds of darkness are found in this life, but the third is at the end of life. Thus, one who follows Christ does not walk in darkness: not in the darkness of ignorance, because I am the truth; nor in the darkness of sin, because I am the way; nor in the darkness of eternal damnation, because I am the life.

6. He next adds the fruit of His teaching, but will have the light of life, for one who has the light is outside the darkness of damnation.

   He says, he who follows me, because just as one who does not want to stumble in the dark has to follow the one carrying the light, so one who wants to be saved must, by believing and loving, follow Christ, who is the light. This is how the apostles followed Him (Matthew 4:20). Because physical light can fail when it sets, it happens that one who follows it meets with darkness. But the light we are talking about here does not set and never fails. Consequently, one who follows it has an unfailing light of life. For the light that is visible does not give life, but gives us an external aid. We live insofar as we have understanding, and this is a participation in this divine light. When this light completely shines upon us, we will then have perfect life: with you is the fountain of life, and in your light we will see the light (Psalms 35:10). This is the same as saying we will have life perfectly when we see this light as it is. Thus we read further on: this is eternal life: that they may know you, the only true God, and Jesus Christ, whom you have sent (John 17:3).

   Note that the phrase, he who follows me, pertains to our merits, while the statement, will have the light of life, pertains to our reward.

7. Beginning with the Pharisees’ objection, the Evangelist presents three statements Jesus makes about Himself. The first is discussed here. The second begins with, again Jesus said to them: I go and you will seek me (John 8:21). The third begins with, amen, amen I say to you: if any man keep my word, he will never see death (John 8:51).

   The first statement He made was, I am the light of the world, and this troubled the Jews. In response, the Evangelist first shows their opposition, and second, how Jesus refuted them by proving His statement was true, beginning with His words, Jesus answered and said to them: although I give testimony about myself.

8. Regarding the first point, it is obvious that what Jesus said in the temple, He said in the presence of the people. But now He is speaking before the Pharisees, and so they said to Him, you give testimony about yourself, but your testimony is not true. They were saying, in effect, that because He was bearing witness to Himself, His testimony was not true.

   Now, in human affairs it is neither acceptable nor appropriate for a person to praise himself: let another praise you, and not your own mouth (Proverbs 27:2). Self-praise does not make a person commendable; being commended by God does: it is not he who commends himself who is approved, but he whom God commends (2 Corinthians 10:18), because only God perfectly knows a person. But no one can sufficiently commend God except God Himself. It is therefore fitting that He bear witness to Himself, and also to men: my witness is in heaven (Job 16:20). Thus, the opinion of the Jews was mistaken.

9. Next, with the words Jesus answered and said to them: although I give testimony about myself, our Lord rejects their opposition. He does this first by the authority of His Father, and second, by answering their objection concerning His Father, which begins with, they therefore said to him: where is your father?

   The opposition of the Jews arose from a certain conclusion they drew. Therefore, first, He shows that their conclusion is not true. Second, He proves that His own testimony is true, beginning with, I do not judge any man.

   Concerning the first point, He does two things. First, He shows that their conclusion is false. Second, He adds the reason for their error, at but you do not know where I come from or where I go.

10. Their conclusion was that the testimony of Christ was not true because He bore witness to Himself. But our Lord says the opposite: that precisely because of this, it is true. Jesus replied, although I give testimony about myself, my testimony is true; and it is true because I know where I came from and where I go. According to Chrysostom, this is like saying, "My testimony is true because I am from God, I am God, and I am the Son of God," for God is truthful (Romans 3:4).

    He says, I know where I came from, that is, My origin, and where I go, that is, to the Father, whom no one but the Son can know perfectly: no one knows the Father except the Son, and he to whom the Son wishes to reveal him (Matthew 11:27). This does not imply that anyone who knows, by love and understanding, where he comes from and where he is going can speak only the truth, for we all come from God and are going to God. But God is truth. How much more, then, does the Son of God speak the truth, He who knows perfectly where He comes from and where He is going.

11. Then, when He says, but you do not know where I come from or where I go, He shows the reason for their error, which was their ignorance of His divinity. It was because they did not know this that they judged Him according to His human nature.

    Thus, there were two reasons for their error. One was that they did not know His divinity; the other was that they judged Him only by His human nature. Regarding the first, He says, you do not know where I come from, that is, My eternal procession from the Father, or where I go. It says below: he who sent me is truthful, and the things that I have heard from him are the same that I speak to the world (John 8:26). And also: from where, then, does wisdom come? (Job 28:20); who will state his origin? (Isaiah 53:8).

    As for the second reason for their error, He says, you judge according to the flesh. This means, "You judge me thinking that I am merely flesh and not God." Or, we could say that "according to the flesh" means wickedly and unjustly. For just as to live according to the flesh is to live wickedly, so to judge according to the flesh is to judge unjustly.

12. Then, at I do not judge any man, He shows that His testimony is true and that it is false to say He alone is bearing witness to Himself. Because judging was just mentioned, He shows first that He is not alone in judging, and second, that He is not alone in bearing witness, at and in your law it is written that the testimony of two men is true.

    He does three things concerning the first point. First, He says that His judgment is deferred. Second, that His judgment is true. Third, He gives the reason why His judgment is true.

13. He mentions that His judgment is deferred when He says, I do not judge any man. He is saying, in effect: "You judge wickedly, but I do not judge any man." As it says above: for God did not send his Son into the world to judge the world, but that the world might be saved through him (John 3:17). Or, we could say, I do not judge any man according to the flesh, as you judge: he will not judge by the sight of his eyes, or reprove by what his ears hear (Isaiah 11:3).

14. Yet, I will judge at some time, because he has given all judgment to the Son (John 5:22). And then, my judgment is true, that is, just: he will judge the people with justice (Psalms 95:10); we know that the judgment of God is according to the truth (Romans 2:2). This shows that His judgment is true.

15. He gives the reason for its truth when He says, because I am not alone. What Christ said before, neither does the Father judge any man (John 5:22), should be understood to refer to the Father in isolation from the Son. Or, He said this because the Father will not appear visibly to all at the judgment. Thus He says, I am not alone, because He is not left alone by the Father, but is with Him: I am in the Father, and the Father is in me (John 14:10).

    This statement rejects the error of Sabellius, who said that the Father and the Son were the same person, the only difference between them being in their names. But if this were true, Christ would not have said, I am not alone, but there is me and the Father who sent me. He would rather have said, "I am the Father, and I am the Son." We should, therefore, distinguish between the persons and realize that the Son is not the Father.

16. Then, at and in your law it is written that the testimony of two men is true, He shows that He is not alone in bearing witness. He does not defer bearing witness as He does His judging. Thus, He does not say, "I do not bear witness."

    First, He mentions the law. Second, He gives His conclusion, at I am one who gives testimony about myself.

17. He says, and it is written in your law—the law that was given to you, for Moses imposed a law ()—that the testimony of two men is true. For it is written: by the mouth of two or three witnesses the issue will be settled (Deuteronomy 19:15).

    According to Augustine, the statement that the testimony of two men is true involves a great difficulty, for it could happen that both of them are lying. Indeed, the chaste Susanna was harassed by two false witnesses (Daniel 13:5 and following), and all the people lied about Christ.

    I answer that the statement, the testimony of two men is true, means that such testimony should be regarded as true when giving a verdict. The reason for this is that true certitude cannot be obtained when human acts are in question. In its place, one accepts what can be considered more certain: what is said by a number of witnesses. For it is more probable that one person might lie than that many would: a threefold cord is not easily broken (Ecclesiastes 4:12).

    When we read, by the mouth of two or three witnesses the issue will be settled (Deuteronomy 19:15), we are led, as Augustine says, to a consideration of the Trinity, in which truth is permanently established and from which all truths are derived. It says, of two or three, because in Sacred Scripture sometimes three persons are enumerated and at other times two persons, in which the Holy Spirit is implied as the bond between the other two.

18. If, therefore, the testimony of two or three is true, my testimony is true, because I am one who gives testimony about myself, and the Father who sent me who gives testimony about me; as stated before: but I have a greater testimony than that of John (John 5:36).

    But this does not seem to be to the point. First, because the Father of the Son of God is not a man, while Christ says, the testimony of two men is true. Second, because there are two witnesses to someone when they are testifying about a third person; but if one testifies about one of the two, there are not two witnesses. Thus, since Christ is testifying about Himself, and the Father is also testifying about Christ, it does not seem that there are two witnesses.

    To answer this, we must say that Christ is here arguing from the lesser to the greater. For it is clear that the truth of God is greater than the truth of a man. Therefore, if they believe in the testimony of men, then they should believe the testimony of God much more. If you receive the testimony of men, the testimony of God is greater (1 John 5:9). In addition, as Chrysostom says, He says this to show that He is consubstantial with the Father and does not need outside testimony.

19. Next, at they said therefore to him: where is your father? we see the question arising about Christ’s Father.

    First, the Evangelist mentions the question asked by the Jews; then Christ’s answer; and third, he indicates the security of Christ.

20. The question the Jews had for Christ was about His Father—where His Father was. They said to him: where is your father? They thought that the Father of Christ was a man, just like their own fathers. Because they heard Him say, I am not alone, but there is me and the Father who sent me, and since they saw that He was now alone, they asked Him, where is your father?

    Or, we could say that they were speaking here with a certain irony and contempt, saying in effect: "Why do you speak to us so often about your Father? Is he so great that his testimony should be believed?" For they were thinking of Joseph, who was an unknown person of low status, and they were ignorant of the divine Father: so the gentiles will not say: where is their God? (Psalms 113:2).

21. Christ’s answer is mysterious: you know neither me nor my Father. Christ does not reveal the truth to them because they were questioning Him not to learn, but to belittle Him. Rather, He first shows them what they were ignorant of, and second, how they might be able to attain knowledge of the truth.

    He shows them their ignorance when He says, you know neither me. He is saying: "You should not be asking about my Father, because you do not know me. Since you regard me as a mere man, you are asking about my Father as though he were a man. But because you do not know me, neither can you know my Father."

22. This seems to conflict with what He said above: you know me, and you know from where I come (John 7:28).

    The answer to this is that they did know Him according to His humanity, but not according to His divinity.

    We should note, according to Origen, that some have misunderstood this and said that the Father of Christ was not the God of the Old Testament. For the Jews knew the God of the Old Testament, according to the verse, God is known in Judea (Psalms 75:1).

    There are four answers to this. First, our Lord says that the Jews did not know His Father because, by not keeping His commandments, they were acting like those who do not know Him. This answer refers to their conduct. Second, they are said not to know God because they did not cling to Him spiritually by love, for one who knows something adheres to it. Third, although they did know Him through faith, they did not have a full knowledge of Him: no one has ever seen God: the only begotten Son, who is in the bosom of the Father, has made him known (John 1:18). Fourth, in the Old Testament the Father was known under the aspect of God Almighty: I appeared to Abraham, to Isaac and to Jacob as God Almighty, but my name, Lord, I did not show them (Exodus 6:3), that is, not under the aspect of Father. Thus, although they knew Him as God Almighty, they did not know Him as the Father of a consubstantial Son.

23. Christ says that He is the way to arrive at a knowledge of the Father: if you did know me. He is saying in effect: "Because I speak of my Father, who is hidden, it is first necessary that you know me; then perhaps you would also know my Father." For the Son is the way to the knowledge of the Father: if you had known me, you would without doubt have known my Father also (John 14:7). As Augustine says, what does if you did know me mean, except, I and the Father are one (John 10:30)? It is customary when you see someone who is like someone else to say, "If you have seen one, you have seen the other"—not that the Son is the Father, but that He is like the Father.

    He says, perhaps, not to indicate doubt, but as a rebuke. It would be like being irritated with your servant and saying to him, "Have you no respect for me? Just remember that I might be your master."

24. The Evangelist shows the security with which Christ answered when he says, these words Jesus spoke in the treasury. We see this security first from the place where He taught: in the treasury, within the temple. The word ‘gazophylacium’ (treasury) is used in Sacred Scripture for the chest in which riches are kept, as gaza is the Persian word for riches and phylax for guard. It is used in this sense: and Jehoiada the priest took a chest and bored a hole in its top, and put it by the altar, to the right of those coming into the house of the Lord. And the priests who kept the doors put into it all the money that was brought to the temple of the Lord (2 Kings 12:9). Sometimes, however, it indicated the building where riches were kept, which is its meaning here.

    We also see Christ’s security in the fact that those who had been sent to arrest Him could not do so, because He was not willing. Thus the Evangelist says, and no man laid hands on him, because his hour had not yet come. This refers to the time for Him to suffer—an hour not fixed by fate, but predetermined from all eternity by His own will. As Augustine says, "His hour had not yet come, not in which He would be forced to die, but in which He would deign to be killed."

25. We may note, according to Origen, that whenever the place where our Lord did something is mentioned, this is done because of some mystery. Thus Christ taught in the treasury, the place where riches were kept, to signify that the coins—that is, the words of His teaching—are impressed with the image of the great King.

    Note also that when Christ was teaching, no man laid hands on him, because His words were stronger than those who wanted to seize Him. But when He willed to be crucified, then He became silent.