Do in Leaves and Wood Among the Bobo and the Bwa
by Christopher D. Roy (1947-2019)
University of Iowa
The Bwa and Bobo should be considered to be distinct ethnic groups, who have drawn on a common pool of religious belief, resulting in many cultural similarities. Among the most important common characteristics is the congregation of Dwo represented by masks of leaves.
The Bobo creator God is called Wuro. He cannot be described and is not represented by sculpture. Bobo cosmogonic myths, wuro da fere, describe the creation of the world by Wuro and the ordering of his creations, which are placed in basic opposing pairs: man/spirits, male/female, village/bush, domesticated/wild, culture/nature, safety/danger, cold/hot, farmer/blacksmith. The balances between forces as they were created by Wuro are precarious, and it is easy for man, through the simplest daily acts, to pollute his world and throw the forces out of balance. Even farming, in which crops are gathered in the bush and brought into the village, can unbalance the precarious equilibrium between culture/nature, village/bush.
Wuro is an otiose creator God, for after creating a perfect world he saw he could not improve upon it; the world was perfect, and its balance ideal but fragile. This balance could be destroyed at any moment, especially by some kind of change.  Wuro also sought to avoid confrontations with man, the most difficult of his creatures. He withdrew from the newly created world, leaving behind part of his own vital material, his son Dwo, the mask, to help mankind. Dwo is the materialization of one form of Wuro, and his principal manifestation. 
Wuro also left behind with man his two other sons, Soxo, the spirit of the bush, of vital force, and Kwere, the spirit that punishes with lightning and thunder. Events that followed the creation by Wuro are explained in a secret language that is taught during initiation.
Dwo is usually revealed to man in the form of a mask (in leaves for the original form, in fibers and with a wooden head for later forms) as bull-roarers and other objects that are kept near the congregation shrine. 
Because Wuro first gave masks to smiths, smiths continue to control their production and use, whether the masks are made of leaves, fibers, or have wooden heads. Dwo, Soxo and Kwere partake of the essential force or spirit of Wuro. These three spirits are the links between man and the forces that control his life. Shrines are erected to them in every Bobo village, each shrine controlled by a congregation priest, dwobore. Because of their relationship to man and Dwo, smiths are most frequently the congregation priests of Dwo, but in contrast are excluded completely from the congregation of Kwere, thunder.
 It is from this religious basis that Bobo resistance to change of any kind stems. The imposition of colonial rule or of a new military government from Ouagadougou all threatened that balance of the Bobo world.
 During the historic period Dwo appeared on many occasions, but to individuals and in special places that people remember to this day. These are villages whose locations are known but which no longer exist. Le Moal calls these numerous appearances "subsequent representations." Among these forms, the Bobo distinguish between the oldest, considered to be the most important, and those that appeared afterward. The first of these "subsequent representations" is, in reality, a triple form, comprising Kwele Dwo, Dwosa, and Sibe Dwo. This form is the object of numerous important cults, and the followers of these cults are called sibe. All other subsequent representations are called Dwosini. Dwo is usually revealed to man in the form of a mask (in leaves for the original form, in fibers for later forms) as bull-roarers and other objects that are kept near the cult shrine.
 The Bobo use several words for "mask". In the north masks are called kore (sing. koro) , something that is old and venerable; in the center of Bobo country they may also be called sowiyera (sing. sowiye), "a disguised man"; in the south the word siye, "the shadow man", the double. In addition, each mask has its own, personal name.