I've read that it may have had origins in African divination systems -- or at least that binary arithmetic was in use from West (Ife) to North (Egypt) Africa fo

I've read that it may have had origins in African divination systems -- or at least that binary arithmetic was in use from West (Ife) to North (Egypt) Africa for centuries before Leibniz. (Eglash, R. 'African Influences in Cybernetics." In C.H. Gray (ed) The Cyborg Handbook. ) Eglash connected Leibniz to that African tradition via his interest in geomancy.