According to the second chapter,
what manner should be observed with them?

Secondly, it is necessary to note what manner of dealing with them should be observed.

And it should be known that they are very curious to hear those things which are of our faith, and especially concerning the Trinity and the Incarnation. And because they surpass reason and exceed the intellect, they neither wish to believe nor can understand them; for in Isaiah, according to another text, it is said, "Unless you believe, you will not understand." ^[1] They are also contrary to the Koran, which they most consistently suppose to be the word of God; and therefore they do not receive them, but mock them. For as it is said in Proverbs, "A fool does not receive words of prudence, unless you speak those things which are in his heart." And therefore they should not be proposed to them, lest they cast pearls before swine, but we should insist first and foremost on showing that their law is vain. "For virtues are not to be implanted unless first the vices are uprooted." ^[2 ]

(14) There is still an easier way to choose in all; but it is easier to show that their faith is frivolous than to prove that our faith is true, because faith is about unseen things and the gift of God. Whence ours has only existence without appearance, but theirs has only appearance without existence. And although we have no reasons to prove the Trinity and other things that are of faith, because then faith would not be faith nor meritorious, we nevertheless have the authority of the gospel, to which both the Koran gives testimony, and we have miracles.

(22) Yet they have neither miracles nor authority. For even if their Koran says of God “you do not say three”, he immediately gives the reason, saying “because there is only one God”. We do not say the opposite of this, but we affirm with them that God is one, whom we say is not only one but also most simple ^[3] . Nor do we give Him a partner or sharer, as they do: the soul of the world or the word or the spirit or a certain divine intellect, as is clear above . (28) Nor is the divine majesty to be equated with the human intellect, as because they cannot understand the distinction of persons without the distinction of essence, which therefore does not exist. Nor do they have effective arguments against this which we cannot easily solve.

And this is sufficient for the defense of the faith.

(33) But more ^[4] we must ask them what their Quran meant by introducing God so often speaking of himself in the plural, since he is one and simple, and this only so that they may be forced to admit the plurality of persons.

(37) But concerning the mystery of the incarnation, which they themselves completely deny and we have on the authority of the Gospel, we must ask them how they know that God was not incarnate.
Either because God could not, and this is false, because since He is omnipotent He can do all things which do not imply contradiction ^[5] .
Or He did not know how to do this, and so the same as before. Or
He did not want to; but "who was His counselor?"
(42) Or He could, as He could make the sun greater or smaller, but He did not do it; and then the proof that He did not do it is pressing upon them. And it is absolutely impossible for them to prove that He was not incarnate.

(46) But this is the proof of Machomet, because he says that Christ did not say that he was God. And although he himself did not say this expressly of himself before the resurrection, yet he sufficiently hinted at it, saying, “I am the beginning, who also speak to you”; and he commended Peter who said this expressly, saying, “Blessed art thou Simon Bar-Jonah,” etc. But he himself did not wish to say this expressly, because he had come secretly to overcome by prudence and humility, and not by power, him who had deceived man by cunning. (52) Hence, for the same reason, before the resurrection, Christ did not say expressly, “I am God,” by which even the fisherman does not say expressly to the fish, “The hook is under the bait.” But after the resurrection, he clearly showed this by giving the Holy Spirit and the authority to forgive sins; hence he said, “Receive the Holy Spirit, whose sins you forgive,” etc. Hence, Thomas also confessed this expressly, saying, “My Lord and my God.”

(58) But given that he himself had not said this expressly about himself , because he himself said humble things about himself and showed magnificent things, it is sufficient that his disciples said this most expressly, who , saying these things ^, performed the same miracles that he had performed.

(61) But since the Saracens themselves would already deny both the miracles of the apostles and their own sayings because they are contrary to the Koran, we must insist on the refutation of so treacherous a law, and show that it is not the law of God, and that the Saracens are bound to receive the authority of the Gospel and the Old Testament. But we can show this by the Koran itself, that Goliath is slain with his own sword.