Ancient Indian sages composed the Kama Shastra on the basis of the Vedas. The first formulation of the Kama Shastra, or the rules of love, is attributed to Nandi, Shiva's companion. It is preserved today in the form of the 'Kamasutra' written down by the sage Vatsyayana sometime between the first and sixth century A.D. The Kama Sutra is recognised as the true surviving text of the original Kama Shastra. Vatsyayana states that he only quotes and condenses the previous work and refers to himself in third person (Vatsyayana thinks ..) when expressing his opinion.
The Kama Shastra was one of three ancient Indian texts concerning the aims of life. It should be understood within the context of the Artha Shastra and the Dharma Shastra (which were written in Sanskrit, seventh century B.C.). As Alain Danielou confirms;
Erotic Kama Sutra Art StatuesLife necessitates three kinds of activity: to assure its survival, its means of existence, and its nourishment; to realise its reproduction according to forms of activity generally connected with sexuality; and, lastly, to establish rules of behaviour that allow different individuals to perform their roles within the framework of the species. In human society, this is represented as three necessities, three aims of life: material goods (artha) assure survival; erotic practice (kama) assures the transmission of life; and rules of behaviour, a moral nature (dharma), assure the cohesion and duration of the species. (The Complete Kamasutra, translated by Alain Danielou, 1994)
So with religion, morality (dharma) and material success (artha), kama is the third goal of human life. Kama is further defined as;
Kama is the enjoyment of appropriate objects by the five senses of hearing, feeling, seeing, tasting and smelling, assisted by the mind together with the soul. The ingredient in this is a peculiar contact between the organ of sense and its object, and the consciousness of pleasure which arises from that contact is called Kama. (Kamasutra, 1883)
Kama is to be learnt from the Kama Sutra (aphorisms on love) and from the practice of citizens. (Kamasutra, 1883)
The ancient Indians appear to be very good evolutionists, as it is clear from evolution that sex and survival are the two most fundamental forces driving our continued existence. Further, the Kama Sutra is an evolutionary work in that it promotes the cultivation of skills to become a well rounded / well evolved individual with healthy, intimate relationships with others. As Alain Danielou agrees;
The Kama Sutra is not a pornographic work. First and foremost, it is a picture of the art of living for the civilised and refined citizen, completing in the sphere of love, eroticism and the pleasures of life. (The Complete Kamasutra, Alain Danielou 1994)