Ramana Maharshi’s teachings on non-duality emphasize the role of the spiritual heart or hridaya as the seat of the Atman and the place of Self-realization. He taught Self-inquiry primarily as a method of tracing our thoughts back to the spiritual heart, in which they can all be dissolved into pure awareness. The same focus on the spiritual heart is perhaps the central teaching of the Upanishads and the ancient Vedic Yoga. 

This approach, however, though simple is not easy. It requires a great power of concentration, not simply as a mental exercise but as the full gathering of our awareness, thought, emotion, sensation and even instinct! The difficulty for the ordinary aspirant, whose thoughts and feelings are scattered at both conscious and unconscious levels, is being able to gather and focus the mind and prana in the heart in order to really set this process in motion. It requires the full energization of the meaning of one’s life and experience, not only through this but through all incarnations!

In this regard, the main obstacle is the prana itself. Our minds naturally move outward with the prana, though the breathing process, our vital functions and the process of sensory perception. We only return to the spiritual heart during one period of the day, this is unconsciously and mechanically in the state of deep sleep. Only a very focused and determined mind can turn this pranic current around and be able take the awareness into the heart and hold it there. It requires the combination of the most consummate insight, purpose and passion. 

In this context, the key practice in Yoga is Pratyahara or withdrawal from the senses. Up to that point all practice is external with body, mind and prana. Pratyhara is the decisive inner turn in which one directs the energy and awareness within. As such, it is the most difficult phase of Yoga, determining whether the Yoga is real or just a play of the outer personality. Pratyahara requires that we switch the polarity of our pranic current, allowing it to flow inward instead of outward.