Atman

आत्मन् - ˈɑːtmən

Spirit or soul. (1)

Atman is the Supreme Self that is immortal and ever-changeless. As the creation and manifestation of God, all beings are and will always be the immortal atman. Although the consciousness of ego may bring the soul to spiritual heights as well as depths of delusion, human beings may choose to realize their true nature as atman. (2) To draw an analogy, the immortal atman countenances the vortices of delusion just as a person standing on a riverbank appraises the whirls and eddies in the river. (3)

The pure consciousness of the atman remains untouched by what the ego sees or experiences. (4) For example, although a person may bear a heavy burden of past karma, the person remains at his center the divine atman. The spark of divinity within him will make him want to correct his past wrongs; it will also make him grateful for the opportunity to pay off past karma as quickly or slowly as pleases him. (5)

The immortal atman may be seen in all the symbols of the universe. Although the universe is vast, it is inferior to the majestic soul because the universe is an outward symbol of the inner world. For example, the stars and the planets are manifestations of divine consciousness, which may be discovered and experienced in the Supreme Self. The moon, as a symbol of human ego, merely reflects the light of divine Spirit. (6)

References
  1. The Jewel in the Lotus, by Swami Kriyananda. Glossary of Indian words.
  2. Demystifying Patanjali, by Swami Kriyananda. Book 1, Sutra 4, “Otherwise (if one hasn’t found inner peace) the vrittis cause the in dwelling Self to assume many (outward) forms.”
  3. Demystifying Patanjali, by Swami Kriyananda. Book 4, Sutra 18, “Because the Atman is unchangeable, the vrittis of chitta are always known to it.”
  4. Demystifying Patanjali, by Swami Kriyananda. Book 2, Sutra 20, “That which sees (experiences through the senses), though apparently colored by the mind, is (in reality) pure consciousness.”
  5. Demystifying Patanjali, by Swami Kriyananda. Book 1, Sutra 31, “Accompanying the obstacles are moodiness, despair, nervous agitation, and agitated breathing.”
  6. The Art and Science of Raja Yoga, by Swami Kriyananda. Step 13, “I. Philosophy: The Anatomy of Yoga, Part 2.”