"Therefore whenever we speak something, we quote from the Vedas, from Vedic literature, to support it. Otherwise it is useless. When you speak something and corroborate it by the quotation from the Bhagavad-gītā, Śrīmad-Bhāgavatam, Upaniṣads—there are so many Vedic literatures—then it is correct. That is the Vedic system. Not that I create knowledge by my research. What is the value of your research?
Because you are imperfect, your senses are imperfect, you cannot even see properly. Even you cannot see your eyelids, so what is the value of your seeing? You cannot see something from a distant place, the nearest place. There must be some adjustment, there must be light under so many conditions you can see. Then what is the value of your eyes?
Vedic knowledge is therefore not seen; it is heard."
Srimad-Bhagavatam 1.2.18 -- Los Angeles, August 21, 1972