Vedanta philosophy accepts the Prasthana Traya texts, the Upanishads, The Bhagavad Gita and the Brahma Sutra as authoritative and primary sources that teach the means to strive for salvation. No study of Vedanta is considered complete without a close examination of the Prasthana Traya texts. The Vedas and the Upanishads are Sruti Prasthana, that is, revealed texts. ‘Sruti’ literally means that which is heard, and is considered as sacred knowledge that has been handed down from days of yore through the oral tradition of communication.
The Bhagavad Gita, the Puranas, etc, are known as Smriti Prasthana. These are the compositions of sages based on their understanding of the valuable insights in the Vedas and their ability to remember and recall these. The Brahma Sutra compiled by Vyasa is known as Nyaya Prasthana or Sutra Prasthana, wherein the philosophical doctrines are analysed logically and systematically. Just as the various river ghats help people to have a dip in the deep waters these texts guide the spiritual aspirant to enter the river of jnana, pointed out Sri R. Krishnamurthy Sastrigal in a discourse. All Vedanta texts speak in one voice about the one and only Brahman who is the sole cause of the universe and of His nature as the essence of eternal consciousness and bliss, sat-chit-ananda. In the Brahma Sutra this is reinforced to show that there is no scriptural text that can be effectively used against the Vedanta teachings. There is no way by which the validity of any system that is opposed to the Vedas can be established in a foolproof manner. Vedanta system makes extensive use of Smriti texts such as Manu Smriti, Vishnu Purana, etc, to argue convincingly about Brahman as the intelligent primary cause of the universe.
