The first 600 pages of this book have completely revolutionized my understanding of Christian spirituality. It was the most complete, detailed, and helpful delineation first of the nature of the Christian life and then of the first two stages of Christian perfection that I have ever read and could ever imagine reading. Fr. Tanquerey is an excellent synthesizer of the great sages and practicers of ascetical and mystical theology - and he adds to the mix a wonderful pastoral spirit of his own that brings these complex and unwieldy ideas into concrete steps accessible to any pilgrim heart.
If you have wandered aimlessly all around the Interior Castle and felt lost in the shadows the Dark Nights, Tanquerey is here to help you understand the prayers, practices, pitfalls, and benchmarks of progression in Christian completeness. It is quite nice to have a handbook written by a Sulpician teacher rather than a Carmelite mystic.
The large bent and intended audience for this text seems to be priests and religious who would offer spiritual direction, and there are many helpful passages about how to assist one's penitent in progressing to the next stage. That said, there is plenty to be gleaned for the mere soul who seeks to draw closer to God. Tanquerey approaches spirituality with an alternating severity and warmth - a true shepherd who has every confidence his flock is going to make it back to the fold.
There was certainly an unsettling sense throughout that Tanquerey had a special laser pointed right at my own pet sins - my glibness, my tendency to sacrifice sincerity at the altar of wit, my joy in the fizzy and superficial. That's a sign of a Spirit-soaked tome, though, and I imagine everyone will find his favorite peccadillos skewered in turn.
Once Tanquerey proceeded into the Unitive Way, the book lost me for a bit. There is something strangely untoward about getting too surgical in such a state of spiritual union. It was rather off-putting to read this dissection - like analyzing a marriage from the outside. He got me right back into it with the section on Extraordinary Mystical Phenomena - who doesn't enjoy a foray into things like levitation, luminous emanations, and stigmata? - and the Diabolical type of such phenomena is always chilling to consider. Back into a big yawn with his brief section on Controverted Questions (the picayune differences between various orders' spiritualities), and then a heart-warming and invigorating Epilogue wherein he matches the stages of spiritual life to the liturgical calendar and then draws us close, close, close into the heart of prayer with Jesus and Mary.
Overall, a more than worthy book to explore - and one that belongs on the library shelf of anyone who is serious about growing in Christlikeness.