Introduction: comparative perspectives on divination and ontology

Many divination systems are epistemologically justified accord-ing to an explicit ontology: results are attributed to the work of an agent (gods, spirits) or to a cosmic principle (as in the Chinese concept qi). Analytically, we can thus distinguish between divination based on ‘agen-tive ontology’, which raises the possibility of deception by gods or spirits, and ‘calculatory ontology’, which understands verdicts as calculations based on fixed principles. The relationship between explicit ontology and epistemic affordance, including the circumstances under which divination is subject to ontological explanation, suggests large-scale comparative questions concerning the wider socio-political and economic correlates of agentive and calculatory systems. These are exemplified in this special issue by the divergences between divination systems in the Greco-Roman world, in Han China, and among the Nuosu