Prabhupāda: That is the process. So how can you deny to understand the supreme science—you can do it independently? No, that is not possible. Therefore it is the verb, the form, gacchet. It is called vidhilinga. You know Sanskrit? Yes. This form of verb is... Perhaps you also know. Gacchet, kuryat, gadyat. These are vidhilinga. Vidhilinga means that is compulsory. Is it not?
Guest (3): Yes.
Prabhupāda: He knows Sanskrit very well. Compulsory. Therefore it is said, gacchet-compulsory. Tad-vijñānārtham... Tat, the transcendental knowledge, vijñāna, that is science. Tad-vijñānārthaṁ sa gurum eva niścayate (MU 1.2.12). Eva is niścayate. Eva means certainly. And again gacchet, "must go." Now, just like to be educated, one must be admitted in a school, must be. Now, what kind of school he has to select, that is another thing, but he must. That's a fact. Similarly, you have to accept a guru. Now, whom you will accept a guru, that is another thing. But you have to do it. That is the injunction of all śāstras. Vedic process is like that. This upanayana, the sacred thread, upanayana. Upa means near, and nayana means bringing. Anayanam, coming or going, like that, nayanam. So "to go near the spiritual master," upanayana.
Guest (3): Upanayana-saṁskāra.
Prabhupāda: Yes. And that sacred thread is the certificate that he has accepted a spiritual master. That is our Vedic system, identity, thread, sacred thread. So the upana... The saṁskāra is called upanayana-saṁskāra. Upanayana means he has gone near the spiritual master. Therefore he is now dvija, second birth. When a person goes to the spiritual master, that is his second birth because he is born foolish. Take birth by the combination of father, mother—that is material birth—that is a birth of ignorance, just like animals. The animals also take their birth in that way. There is no different process, the sex life. So what is the difference between animal and man? Therefore, upanayana, dvija.
Guest: Janmanā jāyate śūdraḥ.
Prabhupāda: Janmanā jāyate śūdraḥ saṁskārad bhaved dvijaḥ. Unfortunately there is no saṁskāra at the present moment. So therefore they remain śūdra. A śūdra means fourth-class. So how a fourth-class man can speculate on the science of God?