So if you can commit mistake, how you can give perfect knowledge? Knowledge means must be perfect, without any mistake, without any illusion. Illusion . . . illusion means to accept something false. The same mistake. And then our imperfectness of the senses: we acquire knowledge; we gather knowledge by perception of our these material senses, but our material senses are imperfect. Just like we are very much proud of our eyes. So I can see under certain condition. Just like if it is not fully lighted, I cannot see what is standing behind; but if there is sufficient light, I can see. Therefore my seeing power is dependent on the varieties of light. So how you can say that whatever you see, it is perfect? I am seeing now things under certain conditions; next moment I will see things under certain other conditions. So as the condition changes, therefore my sight also changes in different ways. Similarly, we have got different senses: our touch, our smell—so many things. All our senses are working under incompetence. Incompetence. So person who has got incompetent senses, who is learned from his mistakes, who is illusioned, whatever knowledge he is giving, that is cheating, because he has no perfect knowledge. So how we can accept knowledge from a person who is liable to so many defects of life? Try to understand. Therefore our process of knowledge is not speculation. What we shall do by speculation? Because my senses, everything, is imperfect; so how can I have perfect knowledge?
So this is not a process of acquiring right knowledge. Our process of acquiring knowledge - to hear from the right person. That is our process. Therefore we are giving so much stress on the Bhagavad-gītā, because Kṛṣṇa is the Supreme Personality of Godhead.