Ontology of naive realism (Lyons 1977, ch. 11.3)

order	definition	examples	properties
1	entities that are said to exist	physical objects: persons, animals, things	relatively constant as to their perceptual properties; located in space and time; publicly observable
2	entities that are said to occur / to take place	events, processes, states-of-affairs	located in time
3	entities that form the object of propositional attitudes	abstract entities: propositions, concepts	have no spatio-temporal location