Charles Johnston 
The Yoga Sutras of Patanjali [EPUB ebook] 

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 physical man: the theme of all mystics in all lands.