From the theoretical or doctrinal perspective three different forms of Thai Buddhism can be distinguished. These are the metaphysical form of Buddhism emphasised by the establishment, the rationalist and doctrinal form espoused by the middle class, and the magical and supernatural form of the religion adhered to by many peasants and urban workers. There is a significant ongoing debate in Thailand about the validity and value of each of the respective metaphysical, rationalist, and supernatural forms of Buddhism. However, because there tends to be a relationship between the form of the religion adhered to and the socio-economic position of the adherent, religious and doctrinal debates also tend to reflect the political conflicts and competition for power between antagonistic sections of Thai society.

Establishment Buddhism

The interpretation of Buddhism supported and most emphasised by the Thai establishment is the traditional royal form of the religion historically used to legitimate the institution of the absolute monarchy. This religious form places particular emphasis on the notion of kamma. The notion of kamma originally denoted an ethical and psychological theory which related a person's present states of well-being or suffering to the moral or immoral quality of his or her past actions. However, this psychological theory was subsequently developed into a sociological theory that equated seniority in the social order with well-being and past morality, and correspondingly related a low social position with present suffering and immorality in previous lives. That is, in the sociological interpretation of kamma those who occupy the most senior positions in the social hierarchy are regarded as having been the most moral in previous existences and so the most deserving to rule in this life. The king was traditionally regarded as the most meritorious person in the kingdom and so was placed at the apex of the social and political order.

This kammic explanation of the traditional monarchical Thai social order was also supported by a metaphysical cosmology involving a hierarchy of multi-levelled heavens and hells inhabited by gods, deities, humans, and demons, according to their respective grades of kammic merit or demerit.