But the highest Person is another — called the Supreme Soul (Paramatman), the inexhaustible Lord who, pervading the three worlds, sustains them.

Here is the pinnacle: there is a third, beyond both the perishable and the imperishable — the Uttama Puruṣa, the Highest Person, called Paramātmā. He pervades all three worlds (the waking, dreaming, and deep sleep states; or the material, subtle, and causal planes) and sustains them all. He is avyaya — inexhaustible, undepleted by the act of sustaining all of creation. The two previous categories — the changing world of beings and the unchanging matrix of the unmanifest — both rest within Him and are sustained by Him. He is not a third option between the two; he is the ground that contains and surpasses both. This is the Purushottama — the Supreme Person — whose introduction gives the chapter its name.