The brāhmaṇa should live by education, by knowledge. Everyone will honor them. They will give the advice to the śūdras, er, to the kṣatriyas. When Paraśurāma killed eleven . . . twenty-one times all the kṣatriyas, his father chastised him that "This is not the business of a brāhmaṇa. My dear son, you are so angry, you have killed all the kṣatriyas and you have killed Kārtavīryārjuna by anger. Oh, you have done great sinful activities. It is not the business of the brāhmaṇa. Therefore you should retire for some time and go to holy places to counteract your sinful activities." This was spoken to Paraśurāma by his father.
So there must be division. A brāhmaṇa can kill anyone simply by words, he is so powerful. But he does not do that. When Viśvāmitra was disturbed by Taraka Rākṣasī in the forest, he came to Dasaratha Mahārāja for help. He could kill that Taraka Rākṣasī simply by his word, but he would not do that. This is not brāhmaṇa's business. He wanted to take the help of a kṣatriya and kill the rākṣasī. Kṣatriya can kill. Brāhmaṇa can take charity. A kṣatriya can exact taxes, and vaiśya be engaged in producing food grains. Kṛṣi gorakṣya-vāṇijyaṁ vaiśya-karma svabhāva-jam (BG 18.44). This is civilization. Aryan civilization means the division must be there. Kṛṣṇa personally says, cātur-varṇyaṁ mayā sṛṣṭaṁ guṇa-karma (BG 4.13). The varṇāśrama must be there. The whole aim is how to please the Supreme Personality of Godhead, because the Supreme Personality of Godhead has to be satisfied.