Haitian Voodoo is a fusion of the traditions of African slaves and Catholic saints practices, those that allowed them to observe their beliefs under the noses of their French masters. Today, many alternate freely between the two faiths. There are varying degrees of participation in the ceremonies. For example, a follower uninitiated, they call vodouisant can go to the ceremonies, advice and medical treatment to a houngan or mambo, and participate in activities related to voodoo. As in other religions, so that it becomes vodouisant houngan or mambo must first undergo a series of rituals and initiation ceremonies.