Self-inquiry is the path of investigating the I-thought back to its source. The investigator looks for the one who looks. Ramana Maharshi taught it in its purest form as the question Who am I?, returned to again and again whenever any thought, feeling, or sensation arises. Not as an intellectual puzzle but as a practical investigation. The thought arises, and the question follows: to whom does this thought arise? When the answer comes, to me, the next question is who is this me?. The I-thought, traced back, dissolves into the awareness from which it arose.
Nisargadatta gave the practice a slightly different shape. The question becomes the simple I am, held without addition. Stay with the bare sense of being, before any qualifier (I am John, I am tired, I am happy) attaches to it. The naked I-am, attended to with patience over months and years, eventually reveals what was always present underneath.
The Direct Path teachers (Atmananda Krishna Menon, Jean Klein, Francis Lucille, Greg Goode) work the same investigation through structured contemplative experiments on the body, the senses, and the mind. Robert Adams brought it to small Los Angeles satsangs in the 1990s in a particularly gentle voice. John Wheeler carries it forward today.
What unites the lineage is the recognition that no doctrine, no belief, and no future event delivers the answer. What is sought is what is already and obviously the case. The work is to notice.