For the Krita are suited the laws of Manu ; for the Treta, those by Gautama (are) prescribed ; for the Dvapara those by Shank and Likhita ; for the Kali, those by Parasara are prescribed. '
The Smritis function as unwritten code of conduct. They lay down Norms of Behaviour in the Society and also are advisory in Nature to kings and his subjects. Smritis also reflect the social Life of the Vedic India down the Ages. There are Eighteen Smritis. These are also called Dharma Sastras,Rules of Righteousness.