 More generally, many ontological dependence  and reduction relationships primarily concern properties: type-identity (Place 1956; Smart 1959; Lewis 1966) and token-identity (Davidson 1980) (see entry on  the mind/brain identity theory),  supervenience (Horgan 1982; Kim 1993; entry on  supervenience);  realization (Putnam 1975; Wilson 1999; Shoemaker 2007),  scientific reduction (Nagel 1961). Moreover, a non-reductive relation such as ontological emergence (Bedau 1997; Paolini Paoletti 2017b) is typically characterized as a relation between emergent properties and more fundamental properties. Even mechanistic explanations often appeal to properties and relations in characterizing the organization, the components, the powers and the phenomena displayed by mechanisms (Glennan &amp; Illari 2018; entry on  mechanisms in science).