In 2011, Stanford University Press published Michael J. Hollerich's English translation: Theological Tractates, by Eric Peterson. I think the best short introduction to the work of Eric Peterson is via the translation of an introduction which Pope Benedict XVI gave, at the 2010 International Symposium. Here's an excerpt:
The starting point of this path is the binding character of sacred Scripture. According to Peterson, sacred Scripture becomes and is binding not as such, it is not only in itself, but in the hermeneutics of the Apostolic Tradition that, in turn, is made concrete in the Apostolic succession and thus the Church maintains Scripture in a living present and at the same time interprets it. Through the bishops, who are in the Apostolic succession, the testimony of Scripture remains alive in the Church and constitutes the foundation for the permanently valid convictions of the faith of the Church, which we find first of all in the creed and in dogma. These convictions are continuously displayed in the liturgy as a living space of the Church for the praise of God. The Divine Office celebrated on earth is, therefore, in an indissoluble relationship with the heavenly Jerusalem: Offered there to God and to the Lamb is the true and eternal sacrifice of praise, of which the earthly celebration is only an image. Whoever participates in the Holy Mass stands almost on the threshold of the heavenly sphere, from which he contemplates the worship carried out by the angels and the saints. Wherever the earthly Church intones her Eucharistic praise, she is united to the festive, heavenly assembly, in which, in the saints, already a part of her has arrived, and gives hope to all those who are still on the way on this earth towards the eternal fulfillment.
Perhaps at this point I should insert a personal reflection. I first discovered the figure of Erik Peterson in 1951. At the time I was chaplain in Bogenhausen, and the director of the local publishing house Kosel, Mr. Wild, gave me the volume, just published, "Theologische Traktate" (Theological Treatises). I read it with increasing curiosity and let myself be truly impassioned by this book, because the theology I was looking for was there: a theology that employs all the historical seriousness to understand and study the texts, analyzing them with all the seriousness of historical research, and not allowing them to remain in the past, but that, in his research, he participates in the self-surmounting of the letter, enters into this self-surmounting and lets himself be led by it and in this way enters into contact with the One from whom theology itself comes: with the living God. And thus the hiatus between the past, which philology analyzes, and the today, is surmounted by itself, because the word leads to the encounter with reality, and the entire timeliness of what is written, which transcends itself toward reality, becomes alive and operating. Thus, from him I learned, in the most essential and profound way, what theology really is, and I also felt admiration, because here he does not only say what he thinks, but this book is an expression of a path that was the passion of his life.
Paradoxically, precisely the exchange of letters with Harnack expresses to the limit the unexpected attention that Peterson was receiving. Harnack confirmed, more than that, he had already written with precedence and independence, that the Catholic formal principle according to which "Scripture lives in the Tradition and the Tradition lives in the living form of the Succession," is the original and objective principle, and that sola Scriptura does not function.
Peterson assumed this affirmation of the liberal theologian in all its seriousness and allowed himself to be shaken, disturbed, bent and transformed by it, and in this way he found the path of conversion. And with it he really took a step as Abraham, according to what we have heard at the beginning of the Letter to the Hebrews: "For here we have no lasting city." He went from the security of a chair to uncertainty, without a dwelling, and he remained during the whole of his life deprived of a sure base and certain homeland, truly on the way with faith and for faith, in the confidence that by being on the way without a dwelling, he was at home in another way and was approaching ever more the heavenly liturgy, which had impressed him.
Given all of this one understands that many thoughts and writings of Peterson remained fragmentary because of the precarious situation of his life, after the loss of teaching, because of his conversion. But even having to live without the security of a fixed salary, he was married here in Rome and constituted a family. With this he expressed in a concrete way his inner conviction that we, though foreigners -- and he was so in a particular way -- find support in the communion of love, and that in love itself there is something that lasts for eternity. He lived this foreignness of the Christian. He had become a foreigner in Evangelical theology and remained a foreigner also in Catholic theology, as it was then.
Today we know that he belongs to both, that both must learn from him all the drama, the realism, and the existential and human need of theology. Erik Peterson, as Cardinal Lehmann affirmed, was certainly appreciated and loved by many, an author recommended in a restricted circle, but he did not receive the scientific recognition that he deserved; it would have been, in some way, too soon. As I have said, Cardinal Lehmann cannot be sufficiently praised for having taken the initiative to publish Peterson's works in a magnificent complete edition, and Mrs. Nichtweib, to whom he has entrusted this task, which she carries out with admirable competence. So the attention given to him through this edition is more than just, considering that now several works have been translated into Italian, French, Spanish, English, Hungarian and even Chinese. I hope that with this, Peterson's thought will be diffused further, which does not stop at details, but always has a vision of the whole of theology. . . .