This is basically just quotations from the lives of the Desert Fathers, linked by comments from Marcel Driot which, I'm afraid, don't add anything very interesting. Driot describes himself as 'a monk and hermit' but, surprisingly, no indication is given of his Order and there is no nihil obstat. The book was originally written in French; the English translation retains a strong Gallic flavour and doesn't read that fluently.
There are better books covering much the same ground, eg those by Thomas Merton and Benedicta Ward.