The Upaniṣads — the philosophical core of the Vedic tradition, revealing the nature of Brahman, the Ātman, knowledge, action and liberation. The ten principal Upaniṣads together with select minor Vaiṣṇava Upaniṣads.
"The Jewel in Yoga's Crown": the circles within the body, the sleeping power, breath, and sound. A practical book with counts and periods, ending with the image of the sun drawing its own radiance back into itself.