Poets and Philosophers who have left behind substantial amount of writing are certainly not ordinary individuals. Apart from understanding the past works, they not only receive fresh ideas intuitively but also struggle to present them systematically for the future generation. The story of their inner lives is hardly known to others except in rare cases who recount autobiographical details. Foucault, in recent times, was a reclusive writer who handled diverse subjects authoritatively. The twist he gave to the concept of history is surely revolutionary. But when we compare him with Sri Aurobindo, the Yoga aspect is missing. The same is the case with Steiner, Gebser, or Wilber.
The Mother & Sri Aurobindo have recorded their forays into the occult worlds to dispel any doubt. None of us can check their veracity but it gives an idea as to how spirituality works and how it is different from common notions of self-realization. Their writings, therefore, stand at a higher level than the works of other great philosophers. Many would classify their output under the rubric of religion but such a distinction seems arbitrary before the Sri Aurobindian dictum, "All life is Yoga." [TNM55]