These are the different steps, how one person can become civilized. So first thing is tapasā. Tapasā brahmacaryena (SB 6.1.13), austerities. Therefore in the Vedic civilization the children, they are taught from the very beginning brahmacarya, tapasā brahmacarya. A small boy, five-years-old boy... That is gurukula. Brahmacārī guru-kule vasan dānto guror hitam (SB 7.12.1). This is a way of life, to teach the brahmacarya, brahmacarya, celibacy, to restrain from sex life. That is brahmacarya.
So this is the beginning of civilization. The unlimited, unrestricted sex life like hogs and dogs, that is not civilization. Civilization, the first of all, to learn how to observe celibacy, to come to the point: no sex life. That is perfect civilization: no sex life. Therefore in the Vedic civilization you'll find the human society is divided into four orders and four spiritual orders, material and spiritual, varṇāśrama. Varṇa and āśrama. Brāhmaṇa, kṣatriya, vaiśya, śūdra, brahmacārī, gṛhastha, vānaprastha, sannyāsa. (break) Sannyāsa means, vānaprastha means, no more sex life. Brahmacārī means no sex life. So out of these four divisions of spiritual life, three divisions no sex life. Brahmacārī, gṛhastha, vānaprastha and sannyāsa.
Brahmacārī is taught from childhood how to keep brahmacārī, brahmacarya. This is the… Anyone who is taught from the beginning of life, "No sex life," then at young age he can control. If you still one cannot control, that…, this gṛhastha life is a concession for sex life. Actually, sex life is not required for advancement of civilization. That is advancement. Why? That if so long we are attached to sex life, we have to remain within this material world—in any form. There are eight million four hundred…Puṁsaḥ striyā mithunī-bhāvam etaṁ (SB 5.5.8). This is… Material world means sex desire. So if one wants to become fit candidate for going back home, back to...: no more sex life. That is civilization.
So sannyāsa means perfectly no more sex life. Vāna…It begins from vānaprastha, retired. It is taught in the brahmacārī. Only in the gṛhastha, restricted sex life; only for begetting nice children. Otherwise, no sex life. Dharma aviruddhaḥ kāmo 'smi (BG 7.11), in the Bhagavad-gita. Dharma aviruddhaḥ means only for getting nice children one should have sex; otherwise no. And in another place it is restricted that one should not become father, one should not become mother, if the parents cannot give protection to the children from the danger of birth, death, old age and disease. This is Vedic contraception, that if you are competent to give instruction to your children how to avoid the cycle of birth, death, old age and disease, then you become father. Otherwise don’t become father, don’t become mother.