 All traditions within Vaishnavism consider the Brahmanas, the Aranyakas and the Upanishads embedded within the four Vedas as Sruti, while Smritis, which include all the epics, the Puranas and its Samhitas, states Mariasusai Dhavamony, are considered as "exegetical or expository literature" of the Vedic texts.The Vedanta schools of Hindu philosophy, that interpreted the Upanishads and the "Brahma Sutra", provided the philosophical foundations of Vaishnavism.Given the ancient archaic language of the Vedic texts, each school's interpretation varied, and this has been the source of differences between the "sampradayas" (denominations) of Vaishnavism.