J.Edward Hackett in this post on phil percs
philosophy and religion
claims that philosophy is unique in that it questions its own ground. Neither science or religion does so. They have a basic ground of 'revelation'. Is this true in the case of all religion? Patently not so in the case of Vedanta if one takes the principle of 'neti, neti' as promulgated in the Upanisads. Not this, not this , means that no conceptual ground is ultimate. The tag 'Vasudeva sarvam idam' or Vasudeva (the father of Krishna) is all this, indicates that reality is self-grounded and therefore no ground at all.
The acceptance of a ground based on revelation is challenged to some extent by apophatic theology. In The Cloud of Unknowing nothing we can conceptualise is adequate to the reality of God. Buried in the aphorism of Eckhart :
The eye with which I see God is the same with which God sees me. My eye and God's eye is one eye, and one sight, and one knowledge, and one love.is the inevitable reduction of God's vision of me to my own personal vision. The ground is always being cut away from under us. One might work in 'humus' and humility here but it's early in the day for such sport.