I have read this book over and over again. Although there are many commentaries on the Yoga Sutras of Patanjali this one is perhaps the best for anyone who originally comes from a Christian background and practises yoga. It might even rekindle your faith. Looking at the faith you are brought up in from a different angle is often quite enlightening and it is worth reading deep Christian literature as much of what is said there is very much along the same lines as the sutras but perhaps not expressed quite so succinctly! Christopher Isherwood gives a deep insight into how the practice of yoga can aid a spiritual aspirant to purify body and mind in order to pursue the spiritual journey and it is fascinating how the commentary refers to the Catholic tradition and draws parallels. The commentary provides guidance on stilling and controlling the mind in order to roll back the veil of illusion and discover the Kingdom of God within ourselves. This book stimulated me to a spiritual search which I might not otherwise have undertaken. Ever grateful to my yoga tutor for recommending this particular commentary. I am now more convinced that yoga is a universal set of tools for the spiritual journey in any tradition. Vedanta appears to be the key.