Dumont says that caste is not a form of stratification but a special form of inequality whose essence has to be deciphered by the sociologists. Here he identifies hierarchy as the essential value underlying the caste system supported by Hinduism. According to Dumont caste divides the whole Indian society into a larger number of hereditary groups distinguished from one another and connected together by three characteristics:
1. Separation on the basis of rules of the caste in matters of marriage and contact whether direct or indirect (food).
2. Interdependent of work or division of labor each group having in theory or by tradition, a profession from which their members can depart only within certain limits
3. Gradation of status or hierarchy which ranks the groups as relatively superior or inferior to one another.
Dumont highlights the state of mind which is expressed by the emergence in various situations of castes. He calls caste system as a system of ideas and values which is a formal comprehensible rational system. His analysis is based on a single principle-the opposition of pure and impure. This opposition underlies hierarchy which means superiority of the pure and inferiority of impure. This principle also underlies separation which means pure and impure must be kept separate. According to Dumont the study of the caste system is useful for the knowledge of India and it is an important task of general sociology. He focused on the need to understand the ideology of caste as reflected in the classical texts, historical examples etc.He advocated the use of an Indological and structuralist approach to the study of caste system and village social structure in India. Dumont in his Homo Hierarchicus has built up a model of Indian civilization based on non-competitive ritual hierarchical system.