Puruṣa is the Ultimate Energy from which all emanates. When Einstein read this verse from the Upaniṣads, written possibly tens of thousands of years ago, he said,🔗

'I felt proud that I had discovered that matter is energy. Many thousand years ago, these Sages knew this, and also knew that matter arises from energy. The last step in science is the first step in spirituality.'

More and more, scientists are beginning to sound like the Eastern Mystics. They no longer have the attitude of scientists of a hundred years ago who felt that they were rewriting the laws of Nature. Our Vedic scriptures said this over thousands of years ago. Śaṅkara has said again and again that the Seer influences what is seen. That was over a thousand years ago. The primal energy principle, puruṣa is like potential energy. It is energy, but passive. It is the operating principle behind the entire Universe. Without this energy, nothing will exist. Nothing will live.

Kṛṣṇa says that there are two kinds of puruṣa: one is eternal, akṣara and one perishes, kṣara. The puruṣa that perishes is the body-mind energy embedded in all beings, including humans. This energy has a definite, limited lifetime. It is always changing. There is nothing permanent about it. It is programmed for deterioration and destruction. The puruṣa that is kūṭastha is the imperishable aspect of this energy. It is the energy of the spirit that is indestructible, akṣara. It is the Soul that is forever, that which cannot be destroyed. Kṛṣṇa points out that primal energy manifests in different ways, as perishable and imperishable. Both are aspects of primal energy. One is destroyed and the other lives. One who realizes this difference and understands the true nature of puruṣa is liberated.