The subject matter of this book was, originally, that of various conversations I had with fellow-priests at days of recollection, study week-ends and retreats and the like; so that the reader should not expect it to be "scientific". Still less should it be treated as a pocket treatise on the Church; I had no intention of doing original research, or doing yet again what has already been done quite satisfactorily by others. What I have done is meditate, in the light of faith, on certain of the aspects of the mystery of the Church, as an attempt to work myself into the very heart of that mystery.
- From the Introduction