The Yoga Sutras of Patanjali are in themselves exceedingly brief, less than ten pages of large type in the original. Yet they contain the essence of practical wisdom, set forth in admirable order and detail. The theme, if the present interpreter be right, is the great regeneration, the birth of the spiritual from the psychical man: the same theme which Paul so wisely and eloquently set forth in writing to his disciples in Corinth, the theme of all mystics in all lands. We think of ourselves as living a purely physical life, in these material bodies of ours. In reality, we have gone far indeed from pure physical life; for ages, our life has been psychical, we have been centred and immersed in the psychic nature. Some of the schools of India say that the psychic nature is, as it were, a looking-glass, wherein are mirrored the things seen by the physical eyes, and heard by the physical ears. But this is a magic mirror; the images remain, and take a certain life of their own.
