The puruṣa—the “person” addressed throughout Indic texts—is not a microcosmic replication of the macrocosmos; he is the phenomenal world itself. This dissertation provides a textual and historical examination of the puruṣa concept in the Vedic Saṃhitās, Brāhmaṇas, Upaniṣads, Pali Nikāyas, pre-classical Saṃhitās of early Āyurveda, and the Mahābhārata. I argue that, contrary to the dominant scholarly position, the cosmos is only ‘in’ the person insofar as the person expands to be the same measure as the cosmos. In the political and religious poetry of the Vedas, the person is modeled after Indra, who creates the world by swelling to its limits in the guise of the Sun. In the Brāhmaṇas, the sacrificer toils to become like Indra, to discover the puruṣa in the Sun, and thereby attain the immortal expansiveness of svarga-loka. In the Upaniṣads, the person is the recursively reproducing, blissfully autophagous eater of the world, who transcends space and time by “yoking” up to ever greater expanses through yoga. In the early teachings of the Buddhist Pāli canon, the person is non-different from the “empty” elementality of the world, and the bhikkhu meditates on this fact to extinguish his belief in self, person, or world. These earlier views of the person are synthesized and given paradigmatic expression in the pre-classical Saṃhitās of Āyurveda and the Mahābhārata, where the logics of Yoga and early Sāṃkhya dictate that person and world are “identical” and “the same measure.” In the words of the foundational Caraka Saṃhitā, the pre-classical person who is fully realized, “bears the yoke” of the world as the sovereign master of its materiality, harmoniously conjoined to the phenomenal totality that is named puruṣa.