According to Veda Vyasa, Ishvara is the Transcendental Person, the supreme inner-controller, and the Atman is intelligence, the laison agent.
In India, it is deemed noble to relinquish that which is not conducive to self-realization, and to cultivate the essential. But some individuals, adopting the uniform of the holy, naked they pray, believe that one's outer appearance is sufficient in order to become free. Yoga itself is a condition of utilizing inner energy by expending none on superficial externals! It is written in the Hatha Yoga Pradipika: "Success in yoga comes through practice, not through adopting a particular kind of dress, nor by reading books". The word yoga is derived from the root word "yuj", which means to harness, i.e. the act of harnessing. Thus we read in Rig Veda of horses that are harnessed to the chariots of the gods such as Indra. It is worth stresing that despite the existence of the Latin noun "jugum" (English 'yoke') from the same Indo-European sources, yoga has never meant 'yoke' in Sanskrit: the tranquil operation of yoking oxen evokes a peaceful, pleasant way of life that has nothing in common with yoga praxis. For in India, the yoke is something used by vaishyas and shudras, whereas the harnessing of horses is a task for kshatriyas like Arjuna. The last point becomes even clearer when we know that the chariots (ratha) we read about in Rig Veda are always military vehicles. Such contexts have the advantage of emphasizing action and restraint that have remained fundamental throughout history. It is from such a battle chariot that Krishna, as the driver, instructs Arjuna in yoga, and their dialogue is the 'Bhagavad Gita'. Apparently, the battle chariot belonged to the aristocrat in ancient India; those wealthy enough to afford one, and its owner was the one who fought in it, usually as the archer. This light but rather inadequately harnessed vehicle (the horse collar had not yet been invented) was very difficult to handle, which conferred great prestige on skilled charioteers. The guild of "sutas", chariot drivers, constituted a high-ranking "jati" belonging to the varna of the kshatriyas. Vishnu, as Krishna, incarnated himself as the driver of Arjuna's chariot, according to Varenne. Thus the Atman is the Supreme inner-controller, as the archer is the owner of the chariot. The driver is intelligence, "buddhi", the laison agent. So, we have in Krishna, the driver, or intelligence, revealing the truth to the Atman - Atman, Pure Consciousness, buddhi, as the Supreme Inner-controller. "The body is like a chariot of which the soul is the owner; the inteligence is its driver; the mind plays the part of the reins. As for the horses, those are the senses; the world is their arena." - Katha Upanishad If you're serious about yoga, read this: 'Yoga and the Hindu Tradition' by Jean Varenne University Of Chicago Press, 1977
