What Is Non-Duality?
As my teacher and friend Francis Lucille writes:
Advaita is a Sanskrit word that literally means “not two”. Synonyms of Advaita are non-duality (nonduality, non duality). Advaita is not a philosophy or a religion. Non-duality is an experience in which there is no separation between subject and object; a “me” and the rest of the universe; a “me” and God. It is the experience of consciousness, our true nature, which reveals itself as absolute happiness, love and beauty. Consciousness is defined as that, whatever that is, which is aware of these very words right here, right now.
The most well-known of nondual spiritual traditions include Buddhist Zen, Ch’an, Dzogchen and Mahamudra; the Advaita Vedanta of Hinduism; and Taoism. The mystical traditions of Islam (viz. Sufism), Judaism (viz. Kabbalah) and Christianity are also expressions of this perennial wisdom.
Using the language specific to Dzogchen, we could say that Teachers of Nonduality abide in the “self-perfected state of all beings” – and transmit this living knowledge directly to those who are interested. Using the language specific to Advaita Vedanta, we could say that the essential understanding and experience is that there is only one Reality — which is Pure Awareness, your True Self.
For a much more detailed introduction to various approaches to nondual inquiry, see Elizabeth’s Review of David Loy’s Nonduality: A Study In Comparative Philosophy. This essay offers distinctions and lines of reasoning that may help to clarify your conceptual understanding.
But remember: The final understanding is wholly non-conceptual and — in its essence — utterly simple!