The 1985 reprint of the 1950 edition is a great guide for one doing Centering or Mental Prayer (Meditation). Fr. Boase, S.J., explains, guides and comforts people whose prayer life may have entered the "Cloud of Unknowing" or the "Dark Night" of St. John of the Cross, a state he calls "The Prayer of Faith".
It is obvious that he both studied and trod this path and counselled many people on it. I found a lot of useful information, guidance and help, and it is written in "modern" prose accessible to non-theologians.
I trully resonated with The Prayer of Faith.