Ibn Warraq, pen-name of the author of Why I Am Not a Muslim, has collected classic texts of Qur'anic studies that date from the late nineteenth century to the 1980s. Many of the early essays in this valuable study grew out of a scarcely disguised antagonism toward a rival faith on the part of Western Jewish and Christian scholars, which gives them a bite lacking in the much later bland, ecumenically-inspired writing.
The essays show the Qur'an's dependence on Jewish and Christian texts as filtered through a polemical sectarian milieu. They imply that the traditional account of the Qur'an's origin via Muhammad ibn ‘Abdallah in Mecca and Medina is highly unlikely, for this version depends on treating much later sources (such as Ibn Ishaq's biography of Muhammad) as reliable history rather than as the late and tendentious back-readings they appear to be. Abandoning such later texts causes the framework that guided the old scholarship to collapse; the probable provenance of the Qur'an then moves to the Fertile Crescent and to the eighth century.
Although latent in the old scholarship, this account of the Qur'an was only brought into focus twenty years ago by John Wansbrough.1 The final essay, by Andrew Rippin, examines Wansbrough's work and explains how he concludes that Muslim sources on the Qur'an and Muhammad are properly understood as "salvation history." As Wansbrough puts it: "We do NOT know and probably never can know what really happened; all we can know is what later people BELIEVED happened, as has been recorded in salvation history." That sums up all that can usefully be said about the origins of the Qur'an.
1 Quranic Studies (Oxford: Oxford University Press, 1977) and The Sectarian Milieu (Oxford: Oxford University Press, 1978).