Sri Ramana Maharshi on Complete Cessation of Mental Activity

Bhagavan: People are so obsessed with and enamoured by mental activity that they imagine that by some special kind of mental activity, such as meditation, for instance, the Self can be duped into revealing Itself. It is not so. Only complete cessation of mental activity can reveal the Self. Giving up the personal self or the idea of the seekers existence, should, again, be volitionless and unconditional; it should not be driven by any motive.
 
If you feel tempted to ask for a formula for this also, know that there is none. You abandon the personal self not because you expect or anticipate or want Self-Realisation in return [in which case you never really abandon it at all – you only absurdly think that you do], but because in that very act of such abandonment, you discover for yourself, practically, as a DIRECT INSIGHT, that no such thing as the personal self ever existed and that no such thing could ever exist.