In many places it is explained. Svanuṣṭhitasya dharmasya saṁsiddhir hari-toṣaṇam (SB 1.2.13). You may accept any kind of dharma. It doesn't matter. Svanuṣṭhitasya dharmasya. But the perfection, how you are becoming perfect in executing your dharma, will be tested how far you have satisfied the Supreme Personality of Godhead. Svanuṣṭhitasya dharmasya.
Ataḥ pumbhir dvija-śreṣṭhā varṇāśrama-vibhāgaśaḥ (SB 1.2.13). Everything is very nicely explained in every śloka, in every chapter of the Vedic literature, especially in the Śrīmad-Bhāgavatam. Svanuṣṭhitasya dharmasya. Ataḥ pumbhir dvija-śreṣṭhāḥ. Ataḥ, "Therefore, after saying so many things," dvija-śreṣṭhāḥ . . . naimiṣāraṇya. Naimiṣāraṇya.
So still Naimiṣāraṇya is there, Nimsar. So in that Naimiṣāraṇya, all the sages assembled, and the conclusion, the resolution was: ataḥ pumbhir dvija-śreṣṭhāḥ. All the great brāhmins, learned brāhmins, dvija-śreṣṭhāḥ . . . dvija. Dvija means brāhmin, kṣatriya, vaiśya, but śreṣṭha means brāhmin. Dvija-śreṣṭhāḥ. Ataḥ pumbhir dvija-śreṣṭhāḥ. Ataḥ pumbhir dvija-śreṣṭhāḥ varṇāśrama-vibhāgaśaḥ.
Because human civilization means accepting this varṇa-āśrama. There must be classification. Not that everyone is the same, everyone on the same level. Everyone on the same level means śūdra, no knowledge. No knowledge, no philosophy, no culture, simply eat, sleep and . . . animals' life.
So ataḥ pumbhir dvija-śreṣṭhā varṇāśrama . . . varṇāśrama-vibhāgaśaḥ must be there. The present civilization is suffering because there is no such thing as varṇāśrama-vibhāgaśaḥ. There is no selection that there must be the most intelligent class of men, brāhmin, the real kṣatriya who can give protection to the people, kṣatriya. That is real kṣatriya. And vaiśya who can actually give protection to the cows and produce agriculture . . . agricultural products and trade. And śūdras, ordinary laborer class. There must be divisions. They must be trained up.
I have repeatedly said in America that there is draft board. They call, conscription, they call any young man to the military department, but most of the boys, young men, they try to avoid this, this military. Most of them. One of the causes of the hippie movement is due to the government's draft board. They want to avoid it.