The Midewiwin or Grand Medicine Society refers to a secret society whose mission was to share the spiritual teachings to the initiated people. People (especially men), who were summoned to be part of this select group had already distinguished themselves with an innate talent for healing. With the help of elders, they learned the teachings and accomplished various levels to enable them to practice their art. In addition to the spiritual aspects of their education, they also learned the use of plants in the treatment of diseases. The Midewiwin Society, like any other school of learning, had several levels or degrees (usually four degrees, but some Aboriginal groups had up to eight). At each level corresponded a pouch (medicine bag) in which the shaman put herbs and items needed for his art. These pouches were made with the skins of certain animals (weasels, mink, bear, lynx).
The major initiation events (birth, puberty, marriage, death, etc.) were written on the scrolls of birch bark, which, with illustrations, explained to the initiated how to practice the rite. It was the elders of the Midewiwin that kept the scrolls, as they were considered sacred and they buried or hid them in the middle of a large rock so that they could not be seen by the eyes of strangers.