Yet this very thing was done mercifully for them, so that they might know their sins and, being converted, merit forgiveness. As for what John says in this place: "Therefore they could not believe, because Isaiah again said, 'He has blinded their eyes and hardened their hearts, lest they should see with their eyes and understand with their heart, and turn, and I should heal them'" (Jn 12:39-40). This seems to contradict the first statement. It seems not to permit us to take "lest they should ever see with their eyes" as meaning, lest they should see with their eyes only for a time. Rather, it seems that what was said plainly should be accepted as meaning that they should not see, since He says clearly. "lest they should see with their eyes." Therefore he says: "Therefore they could not believe." He reveals quite clearly that this blindness was not brought about so that they might one day be moved by it and grieved over not understanding, and then be converted through repentance. For they could not do this unless they first believed, so that by believing they might be converted, by conversion be healed, and by healing understand. Rather, they were blinded because they did not believe. For he says most plainly that they could not believe. If this is so, who would not rise in defense of the Jews and proclaim that they were not guilty because they did not believe? For they could not believe because He had blinded their eyes. But since God must rather be understood as guiltless, we are compelled to acknowledge that they deserved to be blinded because of their other sins. Yet because of this blindness they could not believe. John's words are: "Therefore they could not believe, because Isaiah said that He has blinded their eyes" (Jn 12:39-40). Therefore we try in vain to understand that they were blinded in order to be converted. They could not be converted because they did not believe, and they could not believe because they were blinded. Or can we say without absurdity that some of the Jews were susceptible to healing? Yet they were so inflamed with pride that it was useful for them first not to believe. They were so blind that they did not understand the Lord when He spoke in parables. Since they did not understand the parables, they did not believe in Him. Since they did not believe Him, they crucified Him with the others who were lost. Thus, after His Resurrection, they would be converted when they were humbled even more by the Lord's death, which was bound up with judgment. Then they would love Him who forgave them such a crime. Their pride was so great that it was converted by so great a humiliation. Anyone may think this was not said properly, unless he reads how this is spoken of in the Acts of the Apostles. For this does not contradict what John says: "Therefore they could not believe, because He blinded their eyes, lest they should see." From this statement we conclude that they were blinded so that they might be converted. That is, the Lord's sayings were hidden from them by the darkness of parables. This was so that after His Resurrection they might repent with a more effectual repentance. Blinded by the obscurity of the preaching, they did not understand the Lord's words. Not understanding them, they did not believe in Him. Not believing, they crucified Him. Thus, after His Resurrection, frightened by the miracles performed in His name, they would be pierced by a still greater guilt for their crime. Cast down into repentance, and then receiving mercy for obedience, they would be converted with a still more fervent love. As for those whom this blindness, arising through the language of parables, did not help toward conversion, the prophet speaks of them elsewhere. The Apostle also mentioned this when speaking about the obscurity of tongues: "With other tongues and with other lips I will speak to this people, and even so they will not hear Me, says the Lord" (1 Cor 14:21; Is 28:11). For it would not have been said, "even so they will not hear Me," unless this had been done to give them strength for humble confession, troubled seeking, humble conversion, and fervent love. Such also is the method of bodily medicine (medicinae corporalis). Medicines, for the most part, first wound in order to heal. Even ointments applied to the eyes, if they must be placed inside the eye, cannot help unless they first cloud the sense of sight and trouble it. Nor should it trouble us that the prophet also says: "If you do not believe, you will not understand" (Is 7:9). This may seem to contradict what John says: "Therefore they could not believe, because He blinded their eyes" (cf. Jn 12:40). That is, the parables were spoken in such a way that they could not be understood by them. Someone says: If they had to believe in order to understand, how could they not believe because they did not understand? That is, how could they fail to believe because He blinded their eyes? But what Isaiah says, "If you do not believe, you will not understand," is said of the understanding of ineffable things in which He will abide. When something is said that must be believed, and what is said is not understood, it cannot be believed. Therefore what has been said must be understood in order that it may be believed. Thus one may believe what has been said. But one must believe what could be expressed, so that what could not be expressed may be understood.