Against this Brahmanic sacerdotalism and its caste organization, the reaction noted in the Upanishads (speculative texts), about 1000 500 bce, introduced a mystical conception of the priesthood in Hinduism and subsequently in Buddhism.
Based on a nondualistic reading of the four "great dicta" (mahavakya) of the canonical Upanishads (speculative texts), the monk's main purpose, following the example given by the founder, is to meditate constantly on the literal identity of his atman (the eternal core of an individual) with the brahman (the Absolute).
For nothing gives true peace to our souls except the grace of Christ…" (CWE 70 246), and he sharply criticizes Plato (Phaedrus 246 9) and his followers for their "outlandish blasphemies" involving belief in the transmigration of souls, exactly the sort of speculative Platonic text that he had avoided whenever he cited Plato in a positive sense.
Though the two groups use both Sanskrit and Tamil scriptures, the Vadakalai relies more on Sanskrit texts, such as the Vedas (the earliest sacred scriptures of India), the Upanishads (speculative philosophical texts), and the Bhagavadgita.
In the early 1st millennium bce, Brahmanism emphasized the rites performed by, and the status of, the Brahman, or priestly, class as well as speculation about brahman (the Absolute reality) as theorized in the Upanishads (speculative philosophical texts that are considered to be part of the Vedas, or scriptures).
In the Katha Upanishad, one of the Upanishads (speculative philosophical texts in the Hindu tradition), a man's soul is welcomed in heaven by 500 apsaras (cloud maidens).
Those later works, called Aranyakas, served as a link between the Brahmanas and the Upanishads, the speculative philosophical texts that constitute the latest genre of Vedic literature.
The syllable is discussed in a number of the Upanishads (speculative philosophical texts), and it forms the entire subject matter of one, the Mandukya Upanishad.
Evidence of both these challenges can be found in Vedic literature itself, especially the Upanishads (speculative religious texts that provide commentary on the Vedas), and bhakti literature is full of vignettes in which the small-mindedness of Brahmans is contrasted with true depth of religious experience, as exemplified by poet-saints such as Kabir and Ravidas.
