Just like a carpenter: his son naturally becomes a carpenter by seeing the father's work. So he can be very easily classified as a carpenter. Similarly, formerly, the brāhmaṇa family, kṣatriya family, vaiśya family, they were following the rules and regulations in such a way that naturally a brāhmaṇa's son became a brāhmaṇa. Because he has learned already the brāhmaṇa principle from the parent, so naturally little touch will make him . . . that is initiation. Even though one is born in a brāhmaṇa family, why does he require initiation and sacred thread ceremony? Because simply by taking birth in a brāhmaṇa family one does not become a brāhmaṇa. He has to be raised to the brāhmaṇa standard. Otherwise, there was no initiation, there was no necessity of initiation or offering the sacred thread. That is called saṁskāra. Otherwise, by birth everyone is śūdra. Janmanā jāyate śūdraḥ saṁskārād bhaved dvijaḥ. So it is very good that one has taken his birth in a brāhmaṇa family, but provided he has learned the brāhmaṇa's activities nicely from the parent, he is brāhmaṇa. Kiṁ punar brāhmaṇaḥ puṇyaḥ (BG 9.33).
But if he deviates from the family principle . . . just like in the śāstra it is said that in a higher class family, brāhmaṇa, kṣatriya, especially brāhmaṇa, if the garbhādhāna-saṁskāra is not accepted, the whole family becomes śūdra. Garbhādhāna-saṁskāra. That means begetting the child, there is a ceremony which is called garbhādhāna-saṁskāra. So in the Kali-yuga practically no saṁskāra is performed. Therefore in the śāstra it is said, kalau śūdra-sambhavaḥ. So Vedic process, Vedic principles of accepting, it is not possible in this Kali-yuga, because the garbhādhāna-saṁskāra is not there. In nobody's family there the garbhādhāna-saṁskāra is taken. Sex life is also regulated by garbhādhāna-saṁskāra. Therefore in the Bhagavad-gītā it is said, dharmāviruddhaḥ kāmo 'smi (BG 7.11). Aviruddha, "Sex life which is not against the religious principles, that I am. That sex life I am," Kṛṣṇa says: "I am that sex life." That is godly. But sex life for sense gratification or for prostitution, that is not Kṛṣṇa. That is Kali. So this is the process.