The real science is how to stop this business. That is being advised in Bhagavad-gītā. Janma-mṛtyu-jarā-vyādhi-duḥkha-doṣānudarśanam (BG 13.9). Tyaktvā dehaṁ punar janma (BG 4.9). People do not understand this, that our real problem is not become promoted to the higher position, but to stop this birth, death, old age and disease. That is real problem. So Kṛṣṇa says that gata-saṅgasya. (aside) Don't sit like that. Don't sit like that. Gata-saṅgasya. Because we are getting different types of body in different planets and different spheres of life on account of our association with modes of nature, therefore Kṛṣṇa is advising, gata-saṅgasya, "Don't associate with the modes of material nature. That is your business." Not that, "You associate with the higher modes of nature." Even very good man, goodness, brāhmaṇa, that is also conditioned life. To become brāhmaṇa—satya śamo damas titikṣā ārjava, jñānaṁ vijñānam āstikyaṁ brahma-karma svabhāva-jam (BG 18.42)—very perfect way of life, but that is also risky. Not that . . . everything is risky, because at any moment we can be associated with another quality. And kāraṇaṁ guṇa-saṅgo 'sya (BG 13.22). It is very difficult position, mixture.
Therefore Kṛṣṇa advises that, "You become freed from association of any of the modes of material nature. Any one of them." Gata-saṅgasya. Muktasya. As soon as you become free from the association of the modes of material nature, then you are mukta, muktasya. Gata-saṅgasya muktasya. And how mukti can be achieved, muktasya? How this position can? Now, jñānāvasthita-cetasaḥ. If you are actually situated in knowledge, then you can be mukta. Without knowledge, ignorance . . . just like a man in knowledge, he never commits any mistake lawfully. So he is not a member or subjected to be punished in the prison house, because he has got full knowledge of the law. If anyone knows . . . even ordinary dealing, just like "Keep to the right, keep to the left," you are driving your car. If you are fully aware that, "If I go to the right, it will be criminal," then you are not subjected to be fined. Mukta, if you are in full knowledge. Therefore our first business is to be situated in knowledge. Jñānāvasthita-cetasaḥ.
So this knowledge is being imparted by Kṛṣṇa Himself, Bhagavad-gītā. The beginning of this knowledge is when Arjuna accepted Him as guru. Śiṣyas te 'haṁ śādhi māṁ prapannam (BG 2.7). "Now no more friendly talks. I become Your disciple." So this is the position. Knowledge should be taken from the perfect person. Because if you take knowledge from a person who is defective, your knowledge has no value. You must take knowledge from the perfect. So anyone in this material world, he is defective. Every one of us, we know that we are defective. What is that? We are very much proud of seeing. So what is the value of our seeing? We see under certain condition, that's all. If there is immediately darkness, what is the value of our eyes? We cannot see. So under certain condition because we see, therefore you are not perfect. But if you can see in any condition, that is perfection, not depending on these defective eyes or senses. That is not knowledge. Defective.
Four defects, I have several times explained. One defect is that we commit mistake, everyone. And we become illusioned, accepting something for something. Just like mostly, even educated person, they accept this body, "I am this body." Just like animal. The cats and dogs, they also think that, "I am this body." I have several times told you that I talked with Professor Kotovsky in Moscow. He said: "After finishing this body, Swāmījī, everything is finished." He said like that. And he is a big professor. And according to our Vedic culture, yasyātma-buddhiḥ kuṇape tri-dhātuke sa eva go-kharaḥ (SB 10.84.13). If one is going on under this impression that "I am this body," he is go-khara, ass and cow, (Bengali: Means.) animal.