Upaniṣads—one-hundred and eight Sanskrit treatises that embody the philosophy of the Vedas. Considered the most significant philosophical sections and crest jewels of the Vedas, the Upaniṣads are found in the Āraṇyaka and Brāhmaṇa portions of the Vedas. They are theistic and contain the realizations and teachings of great sages of antiquity; The term upaniṣad literally means that which is learned by sitting close to the teacher. The texts of the Upaniṣads teach the philosophy of the Absolute Truth (Brahman) to those seeking liberation from birth and death, and the study of the Upaniṣads is known as Vedānta, the conclusion of the Veda. The contents of the Upaniṣads are extremely difficult to fathom; they are to be understood only under the close guidance of a spiritual master (guru). Because the Upaniṣads contain many apparently contradictory statements, the great sage Vyāsa systematized the Upaniṣadic teachings in the Vedānta-sūtra. His natural commentary on the Vedānta-sūtra is the Śrīmad-Bhāgavatam. See Śrīmad-Bhāgavatam, Vedānta-sūtra.