Arguments regarding anthropological studies of religion in Myanmar have primarily focused on how to comprehend canonical Theravāda Buddhism and indigenous spiritual worship. In contrast with Spiro’s dualistic argument, which regards Burmese Buddhism and spiritual worship as comprising independent religious fields, Brac de la Perrière does “not consider the spirit cult a religion unto itself, but as part of Burmese religion” and views “Burma’s mainstream religion as a religious system that incorporates within the Buddhist framework practices of seemingly different horizons such as the spirit cult or the weikza cult” [Brac de la Perrière 2009]. Furthermore, Brac de la Perrière indicates that the “nat line” and “dat line”, which are distinguished by ritual specialists such as spiritual mediums, emerged as fluctuating domains in an overall fluid religious landscape [Brac de la Perrière 2014]. Although my study supports the argument of Brac de la Perrière, her study lacks not only non-specialists’ discourses or practices about spiritual beings or “non-human” agencies but also an analysis of Pāli canons concerning spiritual beings, despite canonical knowledge being the main component of the framework of reference for “orthodox” Buddhism. To further develop these arguments, I will focus on practices and discourses of spiritual beings called thaik, which are viewed as an adjunctive subordination of nat [Spiro 1967]. After considering basic configurations about thaik, such as differences between thaik and ouksasaun, the world of thaik, or the relationship between thaik and human beings, I will show how thaiks are written in Pāli canons. Through these arguments, I will indicate that discourses or practices about thaik have appeared through a process of re-rationalization of a group of spiritual beings within the framework of “orthodox” Buddhism based on the criticism of belief in indigenous, unseen spiritual beings. Further, it shall be Pāli canons that boosts the existence and agencies of thaik through the intermediary of rejoicing for transmitting merit (anumodana).