The Guna theory of pollution was proposed by Marvin Davis (1976) who was a student of Marriott and Inden. This theory was derived after interviewing the Hindus of West Bengal but it is also mentioned in the sacred books such as Bhagavada Gita, Srimad Bhagavata Mahaprurana, Purushasukta and the Manva Dharamasastra. According to this theory, the feminine principle called prakriti joins with the male matter called purusha. The union of prakriti and purusha forms three basic materials called gunas. The three gunas are sattvaguna, rajoguna and tomoguna. The sattvaguna is a white substance, generates goodness and joy and inspires all noble virtues and action; rajoguna is red, ‘produces egoism, selfishness, violence, jealousy, and ambition; tamoguna is black, engenders stupidity, laziness, fear, and all sorts of base behavior.’(Davis,1976:9).
The sattvaguna may be treated as symbolic of purity while the tamoguna may be treated as symbolic of impurity. It is believed that all the gunas are present and well balanced in the body of the Brahma while one or the other guna predominates among the four varnas. The proportion of guna in each varna is maintained through the lifestyle, diet, marriage pattern or the inter caste relation. Vegetarian food builds up sattvaguna, non-vegetarian food builds up rajoguna, and beef, left over food, spoiled food, and alcohol build up tamoguna. It is believed that disproportionate admixture of the tamoguna with the sattvaguna or the rajoguna creates, what Stevenson referred to as ‘permanent pollution.’ Brahmins involved in reciting sacred chants, performing sacrifices, and preaching the scriptures largely have sattvaguna. Similarly, untouchables involved in the work of scavenging, tanning, and that which involves dealing with dirt and filth, animal hide, body excretions largely have tamoguna, and Kshatriyas or Vaishyas who are involved in warfare, and activities that sustain life such as cultivation, herding, trading respectively, largely have rajoguna.
It may be understood that people of different varnas and jatis may improve their guna through diet, work, and performance of religious rituals, meditation and learning. Another way in which the guna may be improved is through marriage. In the words of Davis (1976:16), ‘Through activities in accord with dharma and through mixing one’s own physical nature with that of sattvik substances, for example, the defining features of a birth-group are transformed positively and its rank elevated; for in this way individuals of the group and the birth- group as a whole become more cognizant of Brahma and lead a more uplifting, spiritual life.’