Thomas Aquinas

After the Lord showed that his teaching has an illuminating power, here he consequently shows that it has a life-giving power; and first he shows this by word, second by miracle: chapter 11, there, "Now a certain man was sick," etc. Concerning the first he does three things. First he shows that he has the life-giving power; second he shows the manner of giving life, there, "I am the good shepherd," etc.; third he shows the power of giving life, there, "A dissension therefore arose again among the Jews because of these words." The first part is divided into three: for first the Lord proposes a certain parable; second the Evangelist suggests the necessity of its exposition, "This proverb he spoke to them," etc.; third the Lord furnishes the exposition of the parable, there, "Jesus said to them again," etc. Now he proposes the parable to them saying, "Amen, amen I say to you." It indeed consists of two parts, namely concerning the thief and the shepherd of the sheep. Hence concerning it he does three things. First he proposes the condition of the thief and the robber; second, of the shepherd, there, "But he who enters by the door is the shepherd of the sheep"; third, the effect of each, there, "And the sheep follow him," etc.

Now for the understanding of this, first it must be considered who the sheep are, who indeed are the faithful of Christ, and those who are in the grace of God; Psalm 94:7: "But we are his people and the sheep of his pasture"; Ezekiel 34:31: "But you, the sheep of my pasture, are men." The sheepfold of the sheep, therefore, is the congregation of the faithful people; Micah 2:12: "I will gather all of you, Jacob; I will bring together the remnant of Israel; I will put them together as a flock in the fold." But the door of the sheepfold is understood one way according to Chrysostom, and another way according to Augustine.

For according to Chrysostom, Christ calls the sacred Scriptures the door, according to that word of Colossians 4:3: "Praying at the same time for us also, that God may open a door for the word." Now sacred Scripture is called a door, as Chrysostom says, first because through it we have access to the knowledge of God; Romans 1:2-3: "Which he had promised by his prophets in the holy scriptures, concerning his Son, who was made to him of the seed of David according to the flesh." Second, because just as a door guards the sheep, so sacred Scripture preserves the life of the faithful; above, John 5:39: "Search the Scriptures, because you think in them to have life." Third, because a door does not permit wolves to come upon the sheep: thus sacred Scripture keeps heretics away from harming the faithful; 2 Timothy 3:16: "All Scripture, divinely inspired, is useful for teaching, for reproving, for correcting, for instructing in justice." He therefore does not enter by the door who does not enter to teach the people by way of sacred Scripture. Hence the Lord says of such men, Matthew 15:9: "And in vain do they worship me, teaching doctrines and commandments of men"; ibid. v. 6: "You have made void the commandment of God."

This, then, is the condition of the thief: that he does not enter by the door, but from elsewhere. Now he adds "climbs up," which also fits the parable, since thieves not entering by the door climb over the walls and hurl themselves down into the sheepfold. It also fits the truth: because the reason why some teach otherwise than sacred Scripture holds arises chiefly from pride; 1 Timothy 6:3-4: "If any man teach otherwise, and does not agree with the sacred words, he is proud, knowing nothing." And as to this he says "climbs up," namely through pride. He, I say, who thus climbs up from elsewhere, is a thief, by seizing what is not his own, and a robber, by killing what he seizes; Obadiah 1:5: "If thieves had come in to you, if robbers by night, how would you have held your peace?"

And according to this exposition, it is connected to what precedes in this way. For since the Lord had said, "If you were blind, you would not have sin," the Jews could respond and say: it is not from our blindness that we do not believe you, but from your error, on account of which we turn away from you. And therefore the Lord, excluding this, wishes to show that he is not in error, because he enters by the door, that is, through sacred Scripture; that is, he teaches those things which sacred Scripture contains. But against this is the fact that the Lord, further on in this same chapter, explaining, says, "I am the door," etc., from which it seems that by the door Christ ought to be understood. To which Chrysostom says that in this parable the Lord says that he is both the door and the shepherd; hence, according as he calls himself in different ways, the door is spoken of in different ways, because, insofar as he calls himself the shepherd, it is necessary that the door be something other than himself, since the shepherd and the door are not the same thing. But nothing other than Christ can more fittingly be called the door than sacred Scripture, on account of the reasons stated above. Fittingly, therefore, sacred Scripture is called the door.

According to Augustine, here by the door Christ is understood: and this, because it is through him that one enters; Apocalypse 4:1: "After this I saw a great door," etc. Whoever, therefore, enters into the sheepfold, must enter through the door, namely Christ, and not from elsewhere. But it must be noted that to enter the sheepfold belongs both to the shepherd and to the sheep: to the sheep indeed, that it may be preserved there; but to the shepherd, that he may preserve the sheep. If, therefore, you wish to enter as a sheep, that you may be preserved there, or as a shepherd, that you may preserve the sheep, you must enter the sheepfold through Christ, from no other place than through Christ; unlike the philosophers, who treated of the principal virtues, and the Pharisees, who established ceremonial traditions. But these are neither shepherds nor sheep, because, as the Lord says, "he who does not enter by the door into the sheepfold of the sheep," namely through Christ, but from elsewhere, "is a thief and a robber"; because he kills both himself and others. For Christ is the door of the sheepfold, that is, of the congregation of the faithful, and no other; Romans 5:1-2: "We have peace with God through Christ, through whom also we have access by faith into this grace in which we stand, and we glory in the hope of the glory of the sons of God"; Acts 4:12: "There is no other name under heaven given to men, whereby we must be saved."

And according to this exposition it is connected to what precedes in this way. For since they said they saw without Christ, according to what he had said, "Now because you say, We see, your sin remains," the Lord therefore shows this to be false, because they do not enter by the door, saying, "Amen, amen I say to you." Now it must be known that just as he who as a sheep does not enter by the door cannot be preserved; so too neither can he who enters as a shepherd preserve, unless he enters by the door, namely through Christ; and it is through this door that the true shepherds entered, concerning whom Hebrews 5:4: "No man takes the honor to himself, but he that is called by God, as Aaron was." But evil shepherds do not enter by the door, but through ambition, and secular power, and simony; and these are thieves and robbers; Hosea 8:4: "They have reigned, and I knew it not"; that is, I did not approve of it. And he says "but climbs up from elsewhere," because this door, namely Christ, since it is small through humility—Matthew 11:29: "Learn of me, because I am meek"—none can enter except those who imitate the humility of Christ. Those, therefore, who do not enter by the door, climb up from elsewhere, that is, they are proud, and do not imitate him who, though he was God, was made man; and they do not acknowledge their own humility.

Here he treats of the shepherd, and first he sets down the condition of the shepherd; second he shows through signs that this one is the shepherd, there, "To him the doorkeeper opens." Now the condition of the true shepherd is to enter by the door, that is, the testimonies of sacred Scripture; hence he was saying, Luke 24:44: "All things must be fulfilled which are written in the law of Moses, and in the prophets, and in the psalms concerning me." He is called shepherd, Jeremiah 17:16: "I am not troubled, following you as shepherd"; Ecclesiasticus 18:13: "He that has mercy teaches and instructs, as a shepherd does his flock." But if Christ is understood by the door, as Augustine explains, then he who enters by the door thus enters through himself. And this is proper to Christ: for no one can enter the door, namely to beatitude, except through the truth, because beatitude is nothing other than joy concerning the truth. But Christ, insofar as he is God, is the truth: and therefore, insofar as he is man, he enters through himself, namely through the truth, which is himself insofar as he is God. But we ourselves are not the truth itself, but we are sons of light, through participation in the true and uncreated light; and therefore it is necessary for us to enter through the truth, which is Christ; below, John 17:17: "Sanctify them in the truth"; below: "If anyone enters through me, he shall be saved." But if anyone also wishes to enter as a shepherd, it is necessary that he enter by the door, that is, Christ, namely according to his truth, will, and ordination; hence it is said, Ezekiel 34:23: "I will set up one shepherd over them, who shall feed them, my servant David," as if he were saying: they must be given through me, and not through others, or through themselves.

Here he sets down the signs of the good shepherd, which are three. The first is taken from the side of the doorkeeper, namely that he is let in by him; and as to this he says, "the doorkeeper opens." Now this doorkeeper, according to Chrysostom, is he who opens the way to the knowledge of sacred Scripture, who was first Moses, who first received and instituted the sacred Scriptures. And this one opens to Christ, because, as it is said above, John 5:46: "If you did believe Moses, you would perhaps believe me also: for he wrote of me." Or, according to Augustine, the doorkeeper is Christ himself, because he himself brings men in to himself; he says: he opens himself, who explains himself, and we enter only through his grace; Ephesians 2:8: "By grace you are saved." Nor does it matter if Christ, who is the door, is himself also the doorkeeper; for certain things fit together in spiritual matters which cannot be so in bodily matters. But the shepherd and the door seem to differ more than the door and the doorkeeper. Since, therefore, Christ is called both shepherd and door, as has been said, much more can he be called both door and doorkeeper. But if you seek another person as doorkeeper besides Moses and Christ, see the doorkeeper as the Holy Spirit, as Augustine says. For it belongs to the office of the doorkeeper to open the door, and of the Holy Spirit it is said below, John 16:13: "He will teach you all truth." For Christ is the door, insofar as he is the truth.

The second sign is taken from the side of the sheep, namely that they obey him. And this is what he says, "And the sheep hear his voice": which indeed, if considered from the likeness of the natural shepherd, is reasonably said, because, just as sheep recognize the voice of the shepherd through accustomed familiarity, so also the faithful and just hear the voice of Christ; Psalm 94:8: "Today if you shall hear his voice." But against this. Many are the sheep of Christ, who nevertheless did not hear his voice, as Paul. Likewise some heard, and were not sheep, as Judas. To this it could be said, that Judas for that time was a sheep of Christ, as regards present righteousness. But Paul, when he did not hear the voice of Christ, was not a sheep, but a wolf; but the voice of Christ, coming to him, changed the wolf into a sheep. But this answer could be maintained, if it were not contrary to what Ezekiel 4:4 says: "That which was broken you have not bound up, and that which was in error you have not brought back." From which it appears that even when they were broken and erring, they were still sheep. And therefore it must be said that the Lord here speaks of his sheep, not only according to present righteousness, but also according to eternal predestination. For there is a certain voice of Christ which no one can hear except the predestined, namely, "he who shall persevere to the end": Matthew 10:22. Therefore he also says, "and the sheep hear his voice," because they could excuse themselves of their unbelief, saying that not only they themselves, but also none of the rulers believes in him. Hence, responding to this, he says, "and the sheep hear his voice"; as if he were saying: they therefore do not believe, because they are not of my sheep.

The third sign is taken from the acts of the shepherd himself; and as to this he says, "he calls his own sheep by name." Where he sets down four acts of the good shepherd. First indeed, that he knows the sheep. Hence he says that he calls his own sheep by name: in which he shows his knowledge of, and familiarity with, the sheep. For we call by name those whom we know familiarly; Exodus 33:17: "I know you by name." And indeed this belongs to the office of the good shepherd, according to that word of Proverbs 27:23: "Diligently consider the countenance of your flock." And this indeed fits Christ according to present knowledge, or rather according to eternal predestination, which he has known by name from eternity; Psalm 146:4: "Who counts the multitude of the stars, and calls them all by their names"; 2 Timothy 2:19: "The Lord knows who are his." Second, that he leads them out, that is, separates them from the company of the impious; Psalm 106:14: "He brought them out of darkness and the shadow of death." Third, because, having already led them out from the impious, and brought them into the sheepfold, he again leads them out from the sheepfold. First indeed for the salvation of others; Isaiah 66:19: "I will send of them that shall be saved... to Lydia"; Matthew 10:16: "Behold I send you as sheep in the midst of wolves"; namely so that you may make sheep out of wolves. Second, for the direction and way of eternal salvation; Luke 1:79: "To direct our feet into the way of peace." Fourth, he goes before them by the example of good conduct; hence he says, "and he goes before them," which indeed is not so with a bodily shepherd, who rather follows, according to that word of Psalm 77:70: "He took him from following the ewes great with young." But the good shepherd goes before them by example; 1 Peter 5:3: "Neither as lording it over the clergy, but being made a pattern of the flock from the heart." But Christ goes before them in both sendings: because he first underwent death for the teaching of the truth, Matthew 16:24: "If any man will come after me, let him deny himself, and take up his cross, and follow me"; and he went before all into eternal life. Micah 2:13: "He is gone up that shall open the way before them."

Here he treats of the effect of each, namely of the thief, and of the shepherd, upon the sheep, and first he sets down the effect of the good shepherd; second, the effect of the wolf and the thief, there, "But a stranger they do not follow." He says, therefore—since what has been said concerns the conditions of each—that "the sheep follow him," namely him who goes before them. And this indeed is evident, because subjects follow the footsteps of their prelates, as it is said, 1 Peter 2:21: "Christ also suffered for us, leaving you an example, that you should follow his steps"; Job 23:11: "My foot has followed his steps." And this is so, because "they know his voice," that is, they recognize it and delight in it; Song of Songs 2:14: "Let your voice sound in my ears: for your voice is sweet." But the effect of the thief is that the sheep do not follow him for long, but only for a time; hence he says, "but a stranger they do not follow"; that is, they do not follow a lying and heretical teacher; Psalm 17:46: "Strange children have lied to me." Thus also Paul did not follow lying teachers for long. But "they flee from him"; and this is so, because, as it is said, 1 Corinthians 15:33, "evil communications corrupt good manners." And they flee for this reason, because "they do not know," that is, they do not approve, "the voice of strangers," that is, their teaching, which creeps like a canker.