Francis Lucille presents Advaita not as a sectarian doctrine, but as the fundamental understanding that lies at the heart of all authentic spiritual traditions. Advaita, in this sense, is the recognition that consciousness is the singular, non‑dual reality and that the separate, individual self is ultimately illusory. This insight, according to Lucille, is not confined to Indian Vedānta, even though Advaita Vedānta offers one of its clearest and most systematic formulations. Rather, it is a perennial wisdom that surfaces wherever spiritual inquiry reaches its deepest level, even if clothed in very different symbols, myths, and practices.

From this perspective, various traditions are seen as diverse languages pointing to the same realization. In Christian mysticism, for example, the language of union with God and the transcendence of the subject–object split is interpreted as an expression of non‑dual awareness, as exemplified in figures such as Meister Eckhart. In Sufism, teachings on fana, the dissolution of the ego in the Divine, resonate strongly with the Advaitic understanding that only the One truly is. Similarly, in Buddhism—especially in currents such as Dzogchen, Mahāmudrā, and Zen—the emphasis on emptiness and direct recognition of one’s true nature is regarded as another doorway to the same non‑dual reality.

Lucille also acknowledges close affinities with Kashmir Shaivism, which likewise takes consciousness to be the fundamental reality. Across these varied paths, the differences that appear so striking at the level of doctrine or ritual are understood primarily as differences of method, temperament, and cultural expression. What unites them, in this view, is their ultimate aim: the dissolution of the illusion of separation and the recognition that individual consciousness is not other than universal consciousness. Advaita, as Lucille presents it, thus does not compete with other traditions, but rather illuminates their deepest intent and reveals a shared, underlying realization that transcends religious boundaries.