Abstract

According to conceptual reductive accounts, if properties of one domain can be conceptually reduced to properties of another domain, then the former properties are ontologically reduced to the latter properties. I will argue that conceptual reductive accounts face problems: either they do not recognise that many higher-level properties are correlated with multiple physical properties, or they do not clarify how we can discover new truthmakers of sentences about a higher-level property. Still, there is another way to motivate ontological reduction, the truthmaker reductive explanations (TRE). TRE can be given by using resources from John Heil’s truthmaker theory and the a priori entailment view or the a posteriori entailment view. I will argue that we can give these truthmaker reductive explanations if there are various less-than-perfectly similar physical properties that can be the truthmakers of sentences about higher-level properties and the physical similarity between them can explain why an irreducible higher-level property is not needed.