(Prabhupada's lecture - Śrīmad-Bhāgavatam 1.15.44 - Los Angeles, December 22, 1973)
So here it is said, mahātmā, gata-pūrvāṁ mahātmabhiḥ. We have to follow great personalities for advancement of knowledge. Actually we do. We accept authority, go to school, college, to learn something from the teacher, professor. But unfortunately, the teachers, professors, they are all rascals. Therefore we do not get proper education. Wrongly directed. They are changing. Changing is not knowledge. That is not knowledge. Just yesterday we were talking some theosophist. He is changing his view. Formerly it was right; now it is wrong. That is not knowledge. Knowledge means what you accept as right, it must be accepted perpetually right. That is knowledge. That is knowledge.
Just like our principle. Kṛṣṇa says that "I am the Supreme," five thousand years ago. So Arjuna who heard from Kṛṣṇa, he also said, paraṁ brahma paraṁ dhāma pavitraṁ paramaṁ bhavān [Bg. 10.12]. He accepted. I am speaking of five thousand years. Otherwise perpetually. Imaṁ vivasvate yogaṁ proktavān aham avyayam [Bg. 4.1]. Long, long ago, before speaking to Arjuna, this Bhagavad-gītā was spoken to the sun-god, forty millions of years ago. The same principle. In the Bhagavad-gītā: "I am speaking to you the same principle." Not that "Forty millions of years have passed, so things have changed." No. Nothing has changed. The sun forty millions of years ago used to rise from the eastern side. Forty or trillions of years. Still it is rising from the east. Can you make any new thing, "Let the sun rise from the west?" No. That is not possible.