Can you clarify what “private interpretation” is supposed to mean to you and other Catholics, then? I am aware that it is a partial quote from I Peter, but it seems to mean something different to you than I am used to hearing from other Catholics. They use it to set aside arguments that disagree with the official positions of the Catholic Church, claiming that my view is some spurious “private interpretation” and therefore invalid. This, although it is the plain sense of the text.
You, OTOH, used it to imply it would condition a response you might have otherwise made. Advise.
My understanding is that everyone reads the scripture and interprets it for himself under various cultural influences. A Catholic is advised to read the scriptures in the company of the entire Church, that includes the Fathers of the Church, the magisterial teaching, as well as with his own mind. However, since most Catholics don’t have an encyclopedic knowledge of the entirety of the Church doctrines, — I don’t, — it is possible for me or for others to offer something that is at variance with the Church’s teaching. I would not consciously do that, and I believe that so far I presented the Catholic doctrine accurately, but still since we are on this topic, I should give this disclaimer.
I won’t, however, insist on my interpretation if it is shown to me to be at variance. I will instead study and adopt the magisterial teaching. That is, perhaps, the difference between the Protestant (speaking loosely) approach and Catholic or Orthodox approach.
There is a great diversity of interpretations that are available to a Catholic. The Church does not usually define doctrines unless some controversy forces her to it, and she moves very slowly even when the need arises. For example, very little is fixed in how the Revelation is interpreted, or where the covenant with the Jews stands today. There are subtle differences on our topic as well: Thomism sees a bit more active role of God in how He leads his elect compared to Molinism, and both are available to a Catholic.
I would say that it is incorrect to simply say “Your interpretation is private, therefore it is incorrect”. I am sure many would do so here in the heat of the rhetoric, but more accurately they should be saying: “This interpretation is perhaps among the several logical interpretations, but it is not what the Church has taught through the ages. Therefore, it is not what the inspired author meant when he wrote that passage, therefore it is incorrect”.
For example, if someone would argue that God is sometimes not all-knowing based on how the story of the Fall is told, and that the passages where He is described as omniscient are to be read figuratively, that would be a logical (let’s grant him that) interpretation that happens to be not patristically and magisterially correct, because the Church teaches that God is in fact all-knowing. However, if someone argues as I just did, that this passage is there to underscore that it was not God’s active will that Adam and Eve should sin, then that is a private interpretation that does not contradict anything the Church teaches, and so it is an available to a Catholic interpretation.