Why the marriage is there? Just to restrict. Without marriage, the man and woman will be open to so many other men and women. Therefore it is to restrict. One man, one woman. Otherwise, if you associate with so many men and so many women, this is animalism. So in order to check him from the animal life, sex intercourse, the marriage is there. This is the purpose. Therefore sastra. Sastra means simply restrict. One who is accustomed to restriction, he's perfect. Not indulgence. The animals are not restricted. But nowadays, better animal is restricted. They have got a time for sexual intercourse. But these, these animals, the four-, two-legged, two-hands animal, they have no restriction. Any time. Less than animal. Therefore sastra is there.
Lecture on Srimad-Bhagavatam 1.10.13, Mayapura, June 26, 1973