On a cursory inspection, Siamese Buddhism, especially as seen in villages, seems remarkably free from alien additions.  But an examination of ancient buildings, of royal temples in Bangkok and royal ceremonial, suggests on the contrary that it is a mixed faith in which the Brahmanic element is strong.  Yet though this element appeals to the superstition of the Siamese and their love of pageantry, I think that as in Burma it has not invaded the sphere of religion and ethics more than the Pitakas themselves allow.  In art and literature its influence has been considerable.  The story of the Ramayana is illustrated on the cloister walls of the royal temple at Bangkok and Indian mythology has supplied a multitude of types to the painter and sculptor; such as Yomma:  rat (Yama), Phaya Man (Mara), Phra:  In (Indra).  These are all deities known to the Pitakas but the sculptures or images[236] in Siamese temples also include Ganesa, Phra:  Narai (Narayana or Vishnu) riding on the Garuda and Phra:  Isuen (Siva) riding on a bull.  There is a legend that the Buddha and Siva tried which could make himself invisible to the other.  At last the Buddha sat on Siva’s head and the god being unable to see him acknowledged his defeat.  This story is told to explain a small figure which Siva bears on his head and recalls the legend found in the Pitakas[237] that the Buddha made himself invisible to Brahma but that Brahma had not the corresponding power.  Lingas are still venerated in a few temples, for instance at Wat Pho in Bangkok, but it would appear that the majority (e.g. those found at Pra Pratom and Lophburi) are survivals of ancient Brahmanic worship and have a purely antiquarian importance.  The Brahmanic cosmology which makes Mt.  Meru the centre of this Universe is generally accepted in ecclesiastical treatises and paintings, though the educated Siamese may smile at it, and when the topknot of a Siamese prince is cut off, part of the ceremony consists in his being received by the king dressed as Siva on the summit of a mound cut in the traditional shape of Mt.  Kailasa.

Like the Nats of Burma, Siam has a spirit population known as Phis.[238] The name is occasionally applied to Indian deities, but the great majority of Phis fall into two classes, namely, ghosts of the dead and nature spirits which, though dangerous, do not rise above the position of good or bad fairies.  In the first class are included the Phi Pret, who have the characteristics as well as the name of the Indian Pretas, and also a multitude of beings who like European ghosts, haunt houses and behave in a mysterious but generally disagreeable manner.  The Phiam is apparently our nightmare.  The ghosts of children dying soon after birth are apt to kill their mothers and in general women are liable to be possessed by Phis.  The ghosts of those who have died a violent death are dangerous but it would seem that Siamese magicians know how to utilize them as familiar spirits.  The better sort of ghosts are known as Chao Phi and shrines called San Chao are set up in their honour.  It does not however appear that there is any hierarchy of Phis like the thirty-seven Nats of Burma.