Let the Marcionites therefore make their choice: Will it not be just the same inconsistency to desert the prescription of their master, as to have Christ teaching in the interest of men or of the Creator? But "a blind man will lead a blind man into the ditch." Some persons believe Marcion.
(Hom. 9, in Hexameron.) In truth, self knowledge seems the most important of all. For not only the eye, looking at outward things, fails to exercise its sight upon itself, but our understanding also, though very quick in apprehending the sin of another, is slow to perceive its own defects.
(de Qu. Ev. l. ii. q. 9.) Or, He has added the words, Can the blind, lead the blind, in order that they might not expect to receive from the Levites that measure of which He says, They shall give into thy bosom, because they gave tithes to them. And these He calls blind, because they received not the Gospel, that the people might the rather now begin to hope for that reward through the disciples of the Lord, whom wishing to point out as His imitators, He added, The disciple is not above his master.
But the Apostle explains this when he says, He who sows sparingly, (that is, scantily, and with a niggardly hand,) shall also reap sparingly, (2 Cor. 6:9.) (that is, not abundantly,) and he who sows blessings, shall reap also blessings, that is, bountifully. But if a man has not, and performs not, he is not guilty. For a man is accepted in that which he has, not in that which he has not.
The Lord added to what had gone before a very necessary parable, as it is said, And he spake a parable to them, for His disciples were the future teachers of the world, and it therefore became them to know the way of a virtuous life, having their minds illuminated as it were by a divine brightness, that they should not be blind leaders of the blind. And then he adds, Can the blind lead the blind? But if any should chance to attain unto an equal degree of virtue with their teachers, let them stand in the measure of their teachers, and follow their footsteps. Hence it follows, The disciple is not above his master. Hence also Paul says, Be ye also followers of me, as I am of Christ (1 Cor. 1:11.). Since Christ therefore judged not, why judgest thou? for He came not to judge the world, but to show mercy.
As if He said, How can he who is guilty of grievous sins, (which He calls the beam,) condemn him who has sinned only slightly, or even in some cases not at all? For this the mote signifies.
That is to say, first show thyself clean from great sins, and then afterwards shalt thou give counsel to thy neighbour, who is guilty only of slight sins.
This parable he added as a most necessary attachment to what had been said. The blessed disciples were about to be the initiators and teachers of the world. It was necessary for them therefore to prove themselves possessed of everything piety requires. They must know the pathway of the evangelic mode of life and be workmen ready for every good work. They must be able to bestow upon well-instructed hearers such correct and saving teaching as exactly represents the truth. This they must do, as having already first received their sight and a mind illuminated with the divine light, lest they should be blind leaders of the blind. It is not possible for those enveloped in the darkness of ignorance to guide those who are afflicted in the same way into the knowledge of the truth. Should they attempt it, they will both roll into the ditch of carelessness.He overthrew the bragging passion of boastfulness, which most give way, that they may not enviously strive to surpass their teachers in honor. He added, “The disciple is not above his teacher.” Even if some make such progress, as to attain to a virtue that rivals that of their teachers, they will range themselves no higher than their level and be their imitators. Paul shall again support us. He says, “Imitate me, as I also imitate Christ.”
He had previously shown us that judging others is utterly wicked and dangerous. It causes final condemnation. “Do not judge,” he said, “and you shall not be judged.” Do not condemn, and you shall not be condemned. By conclusive arguments, he persuades us to avoid the very wish of judging others. Deliver yourself first from your great crimes and your rebellious passions, and then you may set him right who is guilty of only minor offenses.
[Syncletica] also said, ‘It is dangerous for a man to try teaching before he is trained in the good life. A man whose house is about to fall down may invite travellers inside to refresh them, but instead they will be hurt in the collapse of the house. It is the same with teachers who have not carefully trained themselves in the good life; they destroy their hearers as well as themselves. Their mouth invites to salvation, their way of life leads to ruin.’
Or the sense of this sentence depends upon the former, in which we are enjoined to give alms, and forgive injuries. If, says He, anger has blinded thee against the violent, and avarice against the grasping, how canst thou with thy corrupt heart cure his corruption? If even thy Master Christ, who as God might revenge His injuries, chose rather by patience to render His persecutors more merciful, it is surely binding on His disciples, who are but men, to follow the same rule of perfection.
Now this has reference to the previous parable, in which He forewarned them that the blind cannot be led by the blind, that is, the sinner corrected by the sinner. Hence it is said, Or, how canst thou say to thy brother, Brother let me cast out the mote that is in thine eye, if thou seest not the beam that is in thine own eye?
He also gave them this parable: Can a blind man lead a blind man? Will they not both fall into a pit? The sense of this saying depends on the preceding, where he instructs about giving alms and forgiving injury. If (he says) anger against the violent and greed against the petitioner has blinded you, can you cure his fault with your corrupted mind? Or will not only he who committed the injury but also you, who could not endure it, be considered guilty? But if his wickedness finds you gentle and with a tranquil heart, both he will be moved to repentance, and you will be given the reward of patience, because you are endeavoring to lead the blind with a seeing eye—that is, a serene heart—towards the light.
Or else, If thou judgest another, and in the very same way sinnest thyself, art not thou like to the blind leading the blind? For how canst thou lead him to good when thou also thyself committest sin? For the disciple is not above his master. If therefore thou sinnest, who thinkest thyself a master and guide, where will he be who is taught and led by thee? For he will be the perfect disciple who is as his master.
But the Lord introduces another parable taken from the same figure, as follows, But why seest thou the mote (that is, the slight fault) which is in thy brother's eye, but the beam which is in thine own eye (that is, thy great sin) thou regardest not?
But these words are applicable to all, and especially to teachers, who while they punish the least sins of those who are put under them, leave their own unpunished. Wherefore the Lord calls them hypocrites, because to this end judge they the sins of others, that they themselves might seem just. Hence it follows, Thou hypocrite, first cast the beam out of thine own eye, &c.
[AD 220] Tertullian on Luke 6:39