Perplexity's response to my Questions.

1.

I have noticed that it appears that you do not hold the Scriptures in the same sense as the average Christian would (inspired word of God). If I am wrong, please correct me. But working with this presupposition, my question is if we agreed that Scripture is inspired, does this affect your argument?

Really, the only way I think a theory of inspiration could affect my argument is if it discouraged source criticism. So, if the theory we adopted permitted source criticism (as the Catholic one does) the argument would be unaffected.

2.

Working with the same presupposition, my next question is, if we agreed that Scripture is inspired, how does it affect my argument?

Hmm, well, it could give you what Fr. Raymond Brown calls sensus plenior:

“The sensus plenior is that additional, deeper meaning, intended by God but not clearly intended by the human author, which is seen to exist in the words of a biblical text (or group of texts, or even a whole book) when they are studied in the light of further revelation or development in the understanding of revelation.” - Brown, Raymond Edward. The Sensus Plenior of Sacred Scripture. Baltimore: St. Mary's Univ., 1955., p. 92. Cf. Summa Theologica, P. 1, Q. 1, A. 10.

This could allow for a correlation between Is. 22 and Matt. 16. The problem would be in trying to show that your interpretation is in fact the sensus plenior, and that’s a particularly difficult thing to do. There doesn’t seem to be a principled methodology here.

3.

There are many Church Fathers which speak about Peter as the Rock, as a major leader (if not the leader). If the early Church did not accept this understanding, what is the source of this idea of Peter as Leader and Rock? Where did it come from?

The Catholic interpretation is not that Peter is the rock per se; but that Jesus instituted the papacy (which includes a certain understanding of Peter being the rock). So, I don't think when a father says Peter is the rock (or something relevantly similar) he's thereby saying anything about the Bishop of Rome, necessarily. I would say for a lot of Church Fathers who say Peter is the rock, they derive this through their exegesis. Further, those Church fathers who claim Peter is the rock on the basis of Tradition are probably referring to older exegetes who said Peter is the rock. Tertullian is one of the earliest such exegetes of this text and he says Peter is the rock (although what he means by this contradicts the Catholic understanding). [I think the only earlier interpreter we know of is the opponent to which Tertullian is trying to refute. This person (or persons) thought Church’s akin to Peter derived his ‘power’. Tertullian was refuting this.] He doesn’t indicate he derived his understanding from Tradition, this is just the best he could make sense of the text. I’m of the position that the universal interpretation of the early Church is contrary to the Catholic interpretation so I don’t think we need posit the papacy to account for their understanding.

4.

Focusing on the primary text in question (Matthew 16), how would you interpret the meaning of what Jesus says to Peter?

I think Jesus gives Simon the title Peter to signify the change underwent by acquiring divinely-caused Faith. I think it's this kind of faith which Jesus refers to as the foundation upon which he will build his Church. Further, he promises that his Church (those who have the faith Peter has) will overcome death and rise to new life when he says the Gates of Hell won't overcome 'it'. Cf. Eph. 5:22-27. I think the keys were simply the power to bind and loose sins, given to all the Apostles later in the Gospel. I want to note something though. Like Augustine, I don't think there is any significant doctrinal content here such that people should understand this text in a certain way in order to assent to some binding, important meaning. It seems vague to me. And, I'm with a lot of scholars who don't think Jesus said these words in this context. I'm not sure why Matthew places them here.