In Hinduism
Apophatic movements in Hinduism are visible in the works of Shankara, a philosopher of Advaita Vedanta school of Indian philosophy, and Bhartṛhari, a grammarian. While Shankara holds that the transcendent noumenon, Brahman, is realized by the means of negation of every phenomenon including language; Bhartṛhari theorizes that language has both phenomenal and noumenal dimensions, the latter of which manifests Brahman.
The standard texts of Vedanta philosophy, to which Shankara also belonged, were the Upanishads and the Brahma Sutras. An expression of negative theology is found in the Brihadaranyaka Upanishad, where Brahman is described as "neti-neti" or "neither this, nor that". Further use of apophatic theology is found in the Brahma Sutras, which state:
Whenever we deny something unreal, it is in reference to something real.In Advaita, Brahman is defined as being Nirguna or without qualities. Anything imaginable or conceivable is not deemed to be the ultimate reality. The Taittiriya hymn speaks of Brahman as "one where the mind does not reach". Yet the Hindu scriptures often speak of Brahman's positive aspect. For instance, Brahman is often equated with bliss. These contradictory descriptions of Brahman are used to show that the attributes of Brahman are similar to ones experienced by mortals, but not the same.
Negative theology also figures in the Buddhist and Hindu polemics. The arguments go something like this – Is Brahman an object of experience? If so, how do you convey this experience to others who have not had a similar experience? The only way possible is to relate this unique experience to common experiences while explicitly negating their sameness.
Read more about this topic: Apophatic Theology