In the first of these articles it was explained that the series is being written with the conviction that an historical approach to Christian teaching on the spiritual life, an enquiry into the thought of successive masters on the subjects of prayer and perfection, will be a powerful aid to the deepening of our own understanding of what the knowledge, love and service God means to each one of us today.

The roots of Christian thinking on prayer and the spiritual life are to be found with the Greek Fathers of the East, whose teaching sprang in the early centuries from the Gospel itself, forming a great heritage from which grew the medieval development in Western Christian thought (while the East has preserved, and continues to preserve, the treasures of the patristic heritage), and in the West at the close of the middle ages the systems of the devotio moderna in turn grew out of the medieval developments.