 abstract objects |  cognitivism vs. non-cognitivism, moral |  constructive empiricism |  fictionalism: modal |  imagination |  impossible worlds |  logic and ontology |  mathematics, philosophy of: fictionalism |  mathematics, philosophy of: indispensability arguments in the |  mathematics, philosophy of: naturalism |  models in science |  moral anti-realism |  moral realism |  naturalism |  nominalism: in metaphysics |  nonexistent objects |  Platonism: in metaphysics |  Platonism: in the philosophy of mathematics |  propositions |  realism 