The Upanishads are a collection of texts from the stories that form the basis for the Hindu religion. Their importance in India is still significant, for with the Bhagavad Gita and Brahmasutra the oldest of these nearly 200 texts form the basis of many older Hindu philosophies. Joyce referenced the Mabinogion and the Upanishads to give mother Grogan's tea a certain air of antiquity, and to give Mulligan a certain air of pompous self-importance. None of the men in the tower had any reason to suspect that Grogan's tea was in any ancient texts.