Sri Aurobindo
Letters of Sri Aurobindo
Volume II - Part 1
What X quotes about the limitation of the power of the Guru to that of a teacher who shows the way but cannot help or guide is the conception of certain paths of Yoga such as the pure Adwaitin and the Buddhist which say that you must rely upon yourself and no one can help you; but even the pure Adwaitin does in fact rely upon the Guru and the chief mantra of Buddhism insists on śaraṇam to Buddha. For other paths of sadhana, especially those which like the Gita accept the reality of the individual soul as an “eternal portion” of the Divine or which believe that Bhagavan and the bhakta are both real, the help of the Guru has always been relied upon as an indispensable aid.
I don’t understand the objection to the validity of Vivekananda’s experience; it was exactly the realisation which is described in the Upanishads as a supreme experience of the Self. It is not a fact that an experience gained in samadhi cannot be prolonged into the waking state.