The Yoga Sutra of Patanjali, although often the first text yogis look at, by itself constitutes only a small part of the yogic teachings. It must be studied in context with the Upanishads, the Gita, the Yoga Yajnavalkya, the Puranas, the Tantras, and the medieval siddha texts. The aggregate of these texts, and not the Yoga Sutra by itself, constitute authentic yogic teaching. From the practitioner’s point of view, it is vain to ask about the differences between the sutras and for example the Gita. What is important to learn is their common goal and to what extent the practices support each other. At what times do I need to do this and when is another technique more suitable?
Different yogic texts (shastras) may describe different avenues to the same goal and even different sections of the same avenue. If you study the Sutra alone and consider it the authority on all aspects of yoga, you will find success hard to come by. The Sutra does not deal with all aspects of yoga. In fact, it deals only with very few.
In this context the tendency to study each word of the Sutra, to take it for gospel and see how modern yoga stacks up against it, is a philistine approach. It reminds me of the Dakini who asked Naropa whether he had studied the words of the Tantras? He answered yes, but then she asked him whether he had understood their meaning. When he replied that he had, she threatened to devour him. What is the moral of the story? Naropa was the dean of India’s largest university; he was said to have had 30 PhDs (in ancient days these were probably easier to come by). The Dakini told Naropa to quit his job and go in search of her brother, Tilopa, who— although he appeared to be a beggar living on fish heads discarded by fishermen— embodied some powerful yogic states. The story goes on through many volumes, but the essence is that there is a vast difference between academic studies and direct realization. Which one are you interested in?
There is no right or wrong answer. What I’m suggesting is that if you want to have the direct experience of the mystic, you may have to invest most of your interest in having that experience; reading historical analyses of yogic texts might have to fade into the background as a hobby at best and may completely fall away as your questions are answered by direct experience.
When that direct experience arrives, all questions (including what was the importance of the Yoga Sutra 500 years ago was and whether postural yoga was connected with it at all) will become mere academics. All of these questions fall away when you stand in the triumphant immediateness, totality, and nakedness of the mystical state. Your mind is arrested, past and future disappear, and every hair on your body stands on end. Through your eyes you will then see the infinite and omnipresent super intelligence that is the wellspring of all sacred traditions of humanity.
An excerpt from my forthcoming book Samadhi The Great Freedom.