There are many other similar passages which clearly prove that the class of literature passing under the appelation of _Puranas_ and _Itihasas_ were in existence even in the Vedic period. From these statements it is very difficult to arrive at a conclusion when these works were really written. The various episodes of these works passed orally from one generation to another for many centuries before they were committed to writing. And even after this many interpelations had been added by various writers in the shape of references to contemporaneous events. The ancient Hindu writers were so very modest that they never liked the idea of making their names known as authors. Many works written by those unknown writers passed in the names of their Gurus or spiritual guides. Thus from internal evidence it is not safe to make any attempt for the determination of date or authorship. The only safe course is to give an approximate date based upon the development of thought that is to be seen in various works, making use of the internal evidence as a test for the accuracy of our conclusions. Taking a survey of the various departments of Hindu literature we find that the theory of incarnation and sectarial worship were absolutely unknown to the Vedic writers and took a very meagre proportion even when the Ramayana and the Mahabharata were written. In the Puranas however we see that the entire theology is based on the doctrine of incarnation-the various sects have their rituals and ceremonies definitely laid down and the caste rules introduced with all their severity and force. Besides we also find the doctrines of Vedanta and Sankya explained popularly in the shape of episodes. This clearly proves that whatever may be the actual date of the composition of these works they are long posterior to the Mahabharata and the Ramayana. From the evidence of style, the treatment of subject matter, the account of Creation and Patriarchal families it is clear, that Harivamsha, although it is a sequel to the Mahabharata, was written long after that great work. If it was not written in the same period when the Puranas were composed it was not at least written earlier.