The society should be divided with quality and work. That is scientific society. That quality can be divided into four, because there are three qualities in the material nature—goodness, passion and ignorance. So goodness, those who are qualified in goodness, they can be called as brāhmin. Those who are qualified with passion, they can be called a kṣatriya. Kṣatriya means the politicians, administrators. brāhmin means highly learned scholars, philosophers, theosophist, theologist, priests—like that. They are called brāhmin. So this society's division is already there. Anywhere you go, all over the world, the division is already, because there are three qualities of nature, and any man you find, he must be under one quality. So according to that quality, he is divided as a brāhmin, kṣatriya, vaiśya, śūdra. Quality. Not only quality; action also.
So the society should be divided into four classes of men. That is natural. Just like in your body there are four divisions: the head division, the arm division, the belly division and the leg division. You cannot avoid it. If you simply say that, "I shall keep my head only," that is not possible. If you say that, "I should keep my legs only," no, that will not do. If you say that "I shall keep my hands only," no, that will not do.