The Cambridge History of India, Vol. I: Ancient India v1.c24.8

v1.c24.8

Thus the Purāṇas, like the Mahābhārata, have undergone a complete transformation. Just as the Mahābhārata, originally the story of a war, has been made into a Dharma Çāstra, the main object of which is to inculcate duty, so too the Purāṇas are no longer mere collections of ancient legends. Like the 'Lives of the Saints' they have been applied to purposes of edification. For them the kings of the earth have existed simply to point a moral—the vanity of human wishes: