In the first part of this volume I have laid before the reader reasons which appear to me to show that the Epistle which is known to us as 1 Corinthians was not written (as is generally supposed) in the spring of the same year in which St. Paul left Ephesus, but about a year earlier; and that, consequently, it cannot be the Epistle of whose reception by the Corinthian Church St. Paul first received news from Titus after he had come to Macedonia. The second part gives the proofs which have led me to the conclusion that the Epistle with which 1 Corinthians has for so long a time been wrongly identified has not been totally lost, but that a considerable portion of it has been preserved for us, and is to be found in the last four chapters of the document which appears in our canon as 2 Corinthians. The concluding portion of this volume will enable the reader to see and examine for himself the result of this theory exhibited in a concrete form.
–From the preface