Mechanistic explanations play an important role in the scientific understanding of the mind. Mechanistic explanations reflect the commitments of mechanistic philosophy. This philosophy stresses a methodology based on decomposition into constituent parts and the synergistic integration of their activities. The methodology provides the identity types required for the formulation of explanations targeting the explanandum phenomenon. The basic relationship between mechanisms and their target explananda is mereological. A system is in intrinsic compositional relation to the participation of its constituent parts in the system’s overall functionality. The compositional relation is primarily inter-level. The stability of the system requires also the existence of intra-level causation within the boundaries of minor sub-mechanisms. In combining the compositional relation with intra-level causation mechanistic explanations would track nonreductive relations. Intra-level causation and inter-level compositional effects are also reflective of a mereological relation. The mind-brain system is an example of a mereological relationship and so according to this logic, the mind would be rendered irreducible. Combining both intra-level causation and inter-level material constitution is nevertheless not sufficient to warrant mechanistic explanations being non-reductive. By emphasizing identity types as the bearers of the mereological relation, mechanists in general regard special-sciences and their kinds as actually reducible to the subsuming mechanisms. Applied to the mind-body relation this means the reduction of mind to brain states.
Roque Molina Marchese (Sun,) studied this question.