All the apparatus of learning in the earlier Middle Ages had the ultimate purpose - at least in principle - of making it possible to understand the Bible better. The fathers laid foundations on which their successors built for a thousand years and more, which helped to form and direct the principles of modern criticism. This study looks at the assumptions within which students of the Bible in the West approached their reading, from Augustine to the end of the twelfth century, when distinct skills in grammar and logic made it possible to develop more refined critical methods and to apply fresh tools to the task.