Philosophy or mysticism won’t fail or falter because they go with the land, they go with consciousness. Like serfs we have haybote and turbary. We’re alright, that’s for sure. How do you begin? At the beginning, go on to the end, and then, stop said Alice. The Advaitins of all the merry serfs that I have encountered in my peripatetic peregrinations keep the closest to that original face, the face you had before you were born. Pratibodha videtam or known with every state of consciousness is what the Katha Upanisad declares. How? Because every state is self-luminous, it knows itself as it exists in every moment. Famously the Buddhist Nihilists or Scholiasts of the Void drew this ort from the Vedic matrix and by isolating it made consciousness incoherent, strictly incoherent because there is nothing to bind it together. They ignored the binding problem being fascinated by the synchronic and left the diachronic out of their considerations. All those bundles of perceptions and no one to gather them up. Haybote not exercised lapses as you well know.
The Advaitins keep it very simple and direct. There are mental modifications or vritti, perceptions, experiences, cerebral events or what you will. They are well aware of illusions but are not tempted into founding their philosophy on them rather they take their stand on the normal, everyday veridical.
I see the stone. The stone is in my mind. But how? In one redaction of the original turn of consciousness which is paradoxically called empirical, that is all we have to go on. That fingerpost points to the quaking bog where turbary has lapsed and only the ignis fatuus flits. Advaitins amongst others find that intentionality establishes the object and look for a metaphysical grounding for knowledge in the unity of the substratum that is to say consciousness itself.
Quite obviously you don’t have to think this out in a programmatic way to know it. Here the merry mystic swaggers in with three broad and pointless divisions in his ananda. You have the nature boy, the savikalpa samadhi realisation in which there is the feeling of the absolute unity of everything. This is the aesthetic unity of the substratum. There is following this and regarded as an intensification, the nirvikalpa samadhi or the complete absorption and dissolution of the subject/object division. At this point the devotees panic and begin trying to pour milk and food into the guru’s mouth as they fear he may die and leave them. Next having been brought round or coming round there is the sahaj samadhi, the everyday in which there is no difference in consciousness, it always is what it is.
Zen Saying: First there is a mountain, then there is no mountain, then there is....