Ashtanga yoga comprises of eight steps towards perfection mentioned in the Yoga Sutras. There are many classical texts on yoga. The process of yoga is dealt with even in the Vedic texts – Yoga Tatva Upanishad, Yoga Shika upanishad, Yoga Chudamani Upanishad, etc. to mention a few. But one has to understand that yoga is what is called a “prayoga sastra” or a practical science. It is more about techniques to evolve the human consciousness, rather than a mere philosophy. In that sense, it was Maharishi Patanjali who expounded the science of yoga in systematic way, in his Patanjali Yoga Sutras.