I was honored to write a short memoir as one of the introductions which I called "Gnostic Letters from Bilthoven" (pp. xv-xxi). The piece is rather personal, written out of the years of mail correspondence that took place between Professor Quispel and I (beginning in 1989 and ending shortly before his death).
The book is quite phenomenal, as was Professor Quispel's work generally. He was a person who thought about things from a different angle than most, and he was so well-versed in the classical, patristic and gnostic literature that he was able to make connections between materials and artifacts that many of us would never have considered.
My understanding is that this collection is something that Professor Quispel was putting together just before his death (and Hans finished editing last fall). So there are little updates to his older articles written by Professor Quispel, many of which occur at the end of the original articles.
A number of the articles are well-known pieces that are standards like "The Demiurge in the Apocryphon of John," "The Study of Encratism: A Historical Survey," and "The Gospel of Thomas Revisited." But there are some less well-known pieces that are equally important such as "Marcion and the Text of the New Testament" (1998) where he discusses the scriptural texts known to Marcion and the development of the Western text, and "Valentinus and the Gnostikoi" (1996) where he refutes Markschies' thesis, and "Plotinus and the Jewish Gnostikoi" (2005) which is an amazing synthesis of early Egyptian esotericism. There are also hard-to-get pieces like his important study on Egyptian Christianity "African Christianity before Minucius Felix and Tertullian" (1982). Some pieces have not been published previously like "The Muslim Jesus" or are translated newly from Dutch like "Apocalyptics and Gnosis from Job to Jan van Eyck" (1988) and "The Epistle to the Laodiceans: A Marcionite Forgery" (1950/51) and "Gregory of Nyssa and Mysticism" (1970) or were lectures like "L'Extase de Saint Paul" (1994, 2000, and then his "last word" in Paris).
I could go on and on. There are fifty chapters. I am looking forward to reading this book slowly, with reflection, and listening to Professor Quispel's voice emerge alive from the pages.