Animism, with ancestor-worship, is the primitive belief of the Thai and their neighbors as well, and this formed the first layer of Thai religion. Later on came Buddhism and the Thai adopted it as their national religion. Unlike their neighbors the Burmans, the Thai inherited a fair proportion of Hinduism through the influence of the Cambodians who were in former days a highly hinduized people. Whatever cults and beliefs are adopted by the Thai , they are readily modified to suit their temperament and surroundings. When they adopted Buddhism, they greatly modified their basic belief of animism into the fold of Buddhism. Likewise when they embraced Hinduism, they adapted it as a subordinate to the former. As Buddhism and Hinduism were evolved from one and the same source, i.e. Brahmanism, there was no hindrance to their assimilation. They became in time intermixed completely, and of course tinged with the former animistic belief. There is a Thai saying, particularly among the Thai of the central area where Hinduism still has some force with the elite class, that "Buddhism and Hinduism usually uphold each other". In the northern and north-eastern areas, Hinduism has become weaker and gradually animism has come to the fore, especially in the folkways of the people, but modified greatly of course, through the influence of Buddhism.
To complete the fact, Buddhism as the national religion of Thailand is of the southern school, the Hinayan; but it reveals some traces of the cults of the Mahayana or Buddhism of the Northern School unconsciously practiced. This was due historically no doubt, to the influence of the past Cambodian Empire and Srivijaya Empire of the Malay Peninsula, which for sometime adopted the Buddhism of the Northern School. There are traces of Mahayanism too in the northern area; but this is no doubt derived from a different channel, namely from Burma and Southern China.
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