Some ai extractions, generated by notebooklm.google.com, from Katrijn van Oudheusden‘s book “Beyond Illusion“:

Nondual inquiry, often referred to as self-inquiry or atma-vichara, is a pragmatic method used to experientially confirm the absence of a separate self and discover one’s true nature as Consciousness. Unlike intellectual study, which remains in the domain of the mind, inquiry is a practice of direct experience intended to reveal reality as it is, without the filter of preconceived beliefs.

Key characteristics and components of nondual inquiry include:

• A “Science of the Self”: The sources describe inquiry as a logical, almost scientific approach that uses the human mind to eventually transcend the mind itself. It does not require adherence to a belief system; instead, it asks the individual to test and validate hypotheses through first-hand observation.
• Tracing Consciousness to its Source: The practice involves tracing the contents of your consciousness—such as thoughts, feelings, and sensations—back to their origin in universal Consciousness. This process points the personal “I” back to the universal “I am” where the illusion of a separate self dissolves.
• Direct Questioning: Inquiry utilizes specific prompts and questions, such as “Am I conscious?” or “Am I alive?”, to shift focus away from the content of experience toward the aware presence that is observing that content.
• Distinction from Mindfulness: The author clarifies that nondual inquiry is not mindfulness. While mindfulness often involves being aware of experiences, inquiry is the act of recognizing what is always already the case: the boundless awareness in which the body, mind, and the world manifest.
• Transcending the Mind: Because the mind and the “self” are considered one and the same, the mind cannot be used to “see” the illusion. Inquiry is the “thorn used to extract another thorn,” employing logic to move beyond mental boundaries and achieve a doubtless knowing of one’s essence as Consciousness.

Ultimately, the goal of nondual inquiry is a natural paradigm shift. By investigating “who” is experiencing life, the seeker discovers that the perceived separate “me” is merely an appearance, and their true identity is the boundless Consciousness that observes the self-illusion.