Vedānta-sūtra is known as nyāya-prasthāna, the Upaniṣads are known as śruti-prasthāna, and the Gītā, Mahābhārata and Purāṇas are known as smṛti-prasthāna. All scientific knowledge of transcendence must be supported by śruti, smṛti and a sound logical basis.
According to learned scholars, there are three different sources of knowledge, which are called prasthāna-traya. According to these scholars, Vedānta is one of such sources, for it presents Vedic knowledge on the basis of logic and sound arguments. In the Bhagavad-gītā (13.5) the Lord says, brahma-sūtra-padaiś caiva hetumadbhir viniścitaiḥ: "Understanding of the ultimate goal of life is ascertained in the Brahma-sūtra by legitimate logic and argument concerning cause and effect." Therefore the Vedānta-sūtra is known as nyāya-prasthāna, the Upaniṣads are known as śruti-prasthāna, and the Gītā, Mahābhārata and Purāṇas are known as smṛti-prasthāna. All scientific knowledge of transcendence must be supported by śruti, smṛti and a sound logical basis.