Integrated Information is not Causation: Why Integrated Information Theory’s Causal Structures do not Beat Causal Reductionism

Abstract In a recent work (Grasso et al., 2021), practitioners of the Integrated Information Theory (IIT) claim to have overcome the weaknesses of causal reductionism in producing a coherent account of causation, as causal reductionism would blatantly conflate causation with prediction and could not answer the question of ‘what caused what.’ In this paper, I reject such a dismissal of causal reductionism since IIT anti-reductionists misunderstand the reductionist stance. The reductionists can still invoke a causal account stemming from the causal power of the universe’s basic units and interactions that, eventually, may lead to structures supporting integrated information. Additionally, I claim that the IIT-inspired misunderstanding of causal reductionism originates from the former’s metaphysical deficit, conflating information with causation. However, as a possible way out, if IIT is complemented with a deeper metaphysical ground, such as nested hylomorphism, an improved argument against causal reductionism can be made to work by invoking formal causality as the ultimate cause of integration in natural systems.