A lógica das ordálias na Europa sempre me pareceu bem curiosa (e cruel). Nathan Nunn mostra que procedimento análogo era usado para produzir escravos na África
The chief of the Cassanga used the “red water ordeal” to procure slaves and their possessions. Those accused of a crime were forced to drink a poisonous red liquid. If they vomited, then they were judged to be guilty. If they did not vomit, they were deemed not guilty. However, for those that did not vomit this usually brought death by poisoning. Their possessions were then seized and their family members were sold into slavery."The Long Term Effects of Africa's Slave Trade" Quarterly Journal of Economics, Vol. 123, No. 1, February 2008, pp. 139-176.