We learn something crucial during a satsang between a disciple and Sri Ramana Maharshi. At the end of “Talk 41” of Talks with Sri Ramana Maharshi (PDF), Sri Ramana responds quite decisively to what a disciple says about his spiritual practice (sadhana):

D. [Disciple]: I meditate neti-neti (not this – not this).
M. [Sri Ramana Maharshi]: No–that is not meditation. Find the source. You must reach the source without fail. The false ‘I’ will disappear and the real ‘I’ will be realised. The former cannot exist apart from the latter.

How come Sri Ramana replied so decisively to one who is referring to a key, indeed a staid practice in the Vedantic tradition?

The plot thickens. In fact, in “Talk 25,” while teaching Self-inquiry (vichara or atma vichara), Sri Ramana had suggested there that the early investigation is along the lines of neti neti: one sees that the “I” is not the body (annamaya kosa) nor is the “I” the mental faculty (manomaya kosa). Then why is neti neti, as he implies here in “Talk 41,” not sufficient?

I submit that Sri Ramana is clear about a tendency we may have to ‘stop halfway’ in our inquiry. You can see what I mean after a deep meditation. Perhaps the samskara-vasanas have temporarily subsided during a deep sit–yet later on in the day, they return and wreak havoc.

To be sure, seeing “not this… not this,” one may come to a sense of “I am-ness.” Yet has the source of one’s misery–the ego, or mind–been seen through–or has its apparational and intermittent existence continued here and there?

In brief, the Great Matter has not been resolved. It is Self-inquiry whose essential point is to resolve the Great Matter definitively.

How? By finding the source of the I-thought.

That is, unless you find the source of the ego I, your misery will continue, albeit perhaps intermittently. Neti neti, then, is not enough (though it may be quite helpful) just because it does not go to the source, does not get to the root. Sri Ramana again: “Find the source. You must reach the source [of the rising ego] without fail.” For if you do so, “[t]he false ‘I’ [the ego I] will disappear and the real ‘I’ [the I-I, or Self] will be realised.”