On the one hand, he is on record as agreeing with St. Augustine—indeed with Tradition and the New Testament itself—that "the New Testament lies hidden in the Old and the Old is unveiled in the New." The OT points objectively to Jesus Christ, who sums up in his Person all the truth contained by the OT. Yet that became clear to people only retrospectively, when Jesus "interpreted" the Scriptures for the disciples after his Resurrection (Luke 24: 25-27) and explained how, despite the hostile resistance of most of the Jewish leadership, they are ultimately about him.
And so, on the other hand, Ratzinger notes:
It is of course possible to read the Old Testament so that it is not directed toward Christ: it does not point unequivocally to Christ. And if Jews cannot see the promises as being fulfilled in him, this is not just ill will on their part, but genuinely because of the obscurity of the texts and the figure of Jesus. Jesus brings a new meaning to these texts--yet it is he who first gives them their proper coherence and significance.
There are perfectly good reasons, then for denying that the Old Testament refers to Christ, and for saying, No, that is not what he said. And there are good reasons for referring it to Him—that is what the dispute between Jews and Christians is all about. But this is not all. A great part of the purely historical and critical exegesis, likewise does not read the Old Testament in the sense of pointing forward: it regards the Christian interpretation of it as being inconsistent with the original meaning, or at rate going far beyond it" (God and the World, pg. 209)
That is why it made sense for the Jews to disagree with the early Christians about how to read what both agreed were "the Scriptures." Of course, for a Christian it would not do to say that the Christian interpretation of the OT is "inconsistent with the original meaning," if by 'the original meaning' one means what God meant to convey through the Scriptures. But if by 'the original meaning' one means what the original human authors intended, and how they were understood by their original audience, then it not only makes sense but is true to say that such "was not what was said." For the most part, the Jews insisted on identifying the latter with the former. But if Christianity is true, then the former goes "far beyond" the latter, perhaps even in some cases saying things that the original human authors would not have accepted.The classic case of this is how Matthew 1:23 cites Isaiah 7:14 to support the claim that Jesus was born of a virgin. Matthew was relying on the Septuagint translation of the Hebrew Scriptures into Greek, which uses the term parthenos, meaning "virgin," to translate Isaiah's almah, meaning "young woman." Why that translation? After all, not all virgins are young women and not all young women are virgins. Perhaps the "seventy" Jewish scholars in Alexandria who produced the LXX believed that the Messiah would be born of a literal virgin; but then, perhaps not. We really don't know. They may simply have chosen parthenos as a decorous synonym for 'a young woman' with the implication that the Messiah would be her first-born. At any rate, we have no evidence that first-century Jews assumed the Messiah would be born of a literal virgin. There doesn't appear to have been any consensus among Jews about how to construe Isaiah 7:14 on this particular point. Yet Matthew, or at least the early Church that received his Gospel as canonical, seems serenely confident that it prophesied that Jesus the Messiah was born of a literal virgin.
This is but one instance of how the New Testament in general treats the Old Testament. The NT itself has Jesus himself explaining "the Scriptures,"—i.e., the works comprised by the LXX—as referring to him in various ways that either the original authors of the Scriptures or their audiences do not seem to have had in mind. So if Christianity is true, then the material sense of those Scriptures is far broader than what they formally say. The full material sense—what Scripture scholars call the sensus plenior—is formally brought out only in light of later events, reflections, and interpretations.
Now I've always thought that the Church's collective understanding of divine revelation sometimes develops similarly to how divine revelation itself unfolded, at least as recorded in the Bible. Although divine revelation is definitive and complete in Jesus Christ, so that the faith is "once-handed-on" to the "holy ones" (Jude 3) is complete and may not be added to or subtracted from, the Church can and does deepen her collective understanding of the deposit of faith over time. In some cases, that involves insights and formulations that cannot be deduced from earlier ones and would likely not even have been accepted by many Christians who accepted the earlier ones.
What Fr. Al Kimel says on this point deserves extensive quotation:
Place St Athanasius in the mid-second century. Would it not have been the case that many orthodox bishops would have considered his teaching on the homoousion heretical? Did not the Synod of Antioch in 269 condemn the use of the term homoousios to speak of the Son? Rightly does R. P. C. Hanson refer to the fourth century, not as “the story of a defence of orthodoxy, but of a search for orthodoxy, a search conducted by the method of trial and error” (The Search for the Christian Doctrine of God, pp. xix-xx). Clarity was achieved only by struggle, disputation, creative innovation, and dogmatic definition. Hanson even goes so far as to describe the achievement of Athanasius and the Nicene theologians as a change in doctrine: “There is no doubt, however, that the pro-Nicene theologians throughout the controversy were engaged in a process of developing doctrine and consequently introducing what must be called a change in doctrine” (p. 872). The Catholic will want to insist that this doctrinal alteration was only apparent—the Church always knows the truth of the apostolic revelation and cannot and does not propose falsehood in her formal de fide teaching—but he is happy to acknowledge that dogma does indeed develop in the life of the Church.
Or consider the doctrine of the full divinity and personhood of the Holy Spirit. How many of the Ante-Nicene Fathers explicitly believed what came to be ecumenical dogma? In fact, as Dom Gregory Dix observes, very few indeed:
The doctrine of the full Deity of the Holy Ghost offers an even clearer illustration. It was defined in 381 against the teaching of Macedonius that the Holy Ghost is not God as the Father and Son are God, but is in some way subordinate and intermediate between God and creatures. There is nothing in the N.T. which clearly indicates that the Orthodox doctrine is certainly right, or which is irreconcilable with Macedonianism in some form. Even the baptismal formula of Matt. xxviii.19 can scarcely be pressed (as it was pressed then) in such a sense, seeing that baptism “in the Name of the Lord Jesus” only is scriptural, and so late as the ninth century was still an officially accepted alternative. St. Athanasius and St. Basil both raised the question of the Third Person, but their controversy was waged with those who had followed them against the Arians. They appealed, naturally, to scripture and tradition, and it is notorious how defective in substance their appeal is found to be when it is closely examined. It is also remarkable that in the works which they wrote to vindicate this doctrine both carefully avoid even once applying the decisive word “God” to the Holy Ghost, though in this they are but following earlier writers, even professed trinitarians like Novatian, and the N.T. itself. St. Gregory Nazianzen, “the theologian” par excellence for the East, under whose presidency the Oecumenical Council of 381 actually defined the doctrine, is explicit that there were by “few” who accepted it in his day and that Athanasius was the first and almost the only doctor to whom God had vouchsafed light on this subject (Orat 21.32). Elsewhere he is even more devastatingly honest with the admission that while the N.T. plainly revealed the Godhead of the Son it no more than “hinted at” that of the Holy Ghost, which was now being plainly revealed in his own day (Orat 31.26). This is some distance from talk of “most certain warrants of Holy Scripture.” It was neither Scripture nor Tradition which imposed the dogma of 381, defined by the most thinly attended and least unanimous of all the assemblies which rank as General Councils, but the living magisterium of the Church of that age. And upon that basis only it is accepted today. That the full doctrine of the Spirit’s Godhead was then believed in some sense “everywhere” we may hope, though the evidence is not reassuring. That it had “always” been believed by some we may suppose, though the evidence is at least defective. That it had previously been believed “by all” is demonstrably untrue. An enormous catena can be formed of ante-Nicene writers from St. Clement of Rome in the first century onwards who are either Macedonian Subordinationists or who definitely make the Holy Ghost a creature. One would have hard work to find one ante-Nicene writer who consistently teaches the full Constantinopolitan doctrine—apart from the Montanist Tertullian!
The appeal to an alleged consensus of the Fathers, “that which has been believed everywhere, always and by all,” simply fails as an adequate standard in matters of doctrinal controversy; and it does so for the simple reason that it presumes a time when the Church uncontroversially, explicitly, and infallibly taught the propositional fullness of the Catholic faith. But such a golden time has never existed. The Church as Church knows the totality of the deposit of faith; but this knowledge at any given point in history is only partially discursive. Her grasp of the revelation may be described as akin to Michael Polanyi’s conception of tacit knowledge: “We know more than we can tell.” Gerald Jantzen’s summary of A. N. Whitehead is also apposite: “We experience more than we know; and we know more than we can think; and we think more than we can say; and language therefore lags behind the intuitions of immediate experience.” Newman has taught us that the Church lives in history and that her formal teaching will and must develop as new questions are put to her both by the world and by her own theologians, thus requiring her to speak in words that which is deeper than words. “The Church’s teaching lives forward,” explains Richard John Neuhaus, “and no definition, including that of councils, is entirely adequate to the whole of the truth.”Indeed. It is just such a perspective which Ratzinger brings to the Scriptures themselves. That kind of understanding, both of the unfolding of divine revelation itself and of the subsequent development of doctrine, is distinctively Catholic. It opposes any theological perspective that precludes development beyond a certain point, such as Scripture or the Fathers. It does not negate anything definitive, but requires holding in tension apparent opposites so that new insight into eternal truth may be achieved.
The more I think about that, the more it seems to me an excellent reason to be Catholic.