Meta Ontology

A pigeon has been conditioned to peck at red objects and has also been conditioned to peck at triangular objects. The pigeon is now presented with a red triangle and pecks. In virtue of which of the object's properties did the pigeon peck? I argue that the disjunctive property "red or triangular" best answers this question and that this in turn gives us reason to admit such disjunctive properties to our ontology. I also show how the criterion for causal efficacy that I employ, expressed in terms of counterfactual conditionals, works to preclude spurious disjunctive properties from counting as efficacious