The Seba library treats Aum in 8 passages, across 4 authors (including Zimmer, Heinrich, Campbell, Joseph, Singh, Jaideva).
The Fourth is soundless: unutterable, a quieting down of all the differentiated manifestations, blissful-peaceful, nondual. Thus OM is Ātman, verily.
Zimmer's Mandukya-derived analysis establishes the four-part structure of OM—A as waking, U as dream, M as deep sleep, and the Silence as Turīya—as the complete symbolic map of Ātman-Brahman.
, Philosophies of India, 1951thesis
A—is the state of waking consciousness, together with its world of gross experience. U—is the state of dreaming consciousness… M—is the state of dreamless sleep… The Silence following the pronunciation of the three, A, U, and M, is the ultimate unmanifest.
Zimmer explicates Aum's halo-of-flames symbolism in Shiva Nataraja as simultaneously signifying the totality of creation, the energy of Wisdom, and the mystical syllable whose three sounds map onto the three states of consciousness.
, Myths and Symbols in Indian Art and Civilization, 1946thesis
'AUM!' we read, for example: This imperishable Syllable is all this. That is to say: All that is Past, Present, and Future is AUM.
Campbell cites the Upanishadic declaration that AUM is coextensive with all time and existence, framing it as the foundational creative utterance that predates and generates the universe.
, Oriental Mythology: The Masks of God, Volume II, 1962thesis
the Silence that is no silence but to be heard resounding through all things, whether of waking, dream, or dreamless night— as surrounding, supporting, and suffusing the syllable AUM.
Campbell positions Aum as the auditory symbol of the primordial Silence that underlies and pervades all states of consciousness, equating it with the Anahata sound of the Void as ground of being.
, Myths to Live By, 1972thesis
When you recite 'auṃ', 'auṃ'-kāra, you recite 'auṃ'-kāra in its grossness, and that grossness ends in 'ma'-kāra ('a-u-ma'). That grossness is over. Then comes its subtleness.
Singh's Kashmirian Shaiva commentary provides a phenomenological practice: the practitioner moves the recitation of Aum through gross, subtle, and subtlest phonological registers until pure Silence—Shiva—is attained.
, Vijnana Bhairava: The Manual for Self-Realization, 1979thesis
aum (a sacred syllable), 90–91… awe… and the aum, 90–91 and personal myth, 89, 90, 91, 104
Campbell's index entry associates Aum explicitly with the experience of awe and with personal myth, indicating its role as a threshold symbol in his developmental psychology of transformation.
, Pathways to Bliss: Mythology and Personal Transformation, 2004supporting
Shakti, Shiva! Dark hidden Father!... Aum! Baum! Pyjaum! I am the light of the homestead, I am the dreamery creamery butter.
Jung quotes Joyce's Ulysses to illustrate how even in degraded, parodic discourse the noblest spiritual treasures—here invoked through the Shakti-Shiva-Aum complex—are never entirely lost from the psyche.
, The Spirit in Man, Art, and Literature, 1966supporting
heartbeat of, 205… Shiva as personification of, 124–5, 135, 167, 204–5
The index entry for the Absolute in Zimmer's compendium places the heartbeat metaphor—closely associated with Aum's rhythmic function—within the broader symbolic field of Shiva and the Absolute.
, Myths and Symbols in Indian Art and Civilization, 1946aside