Antiobjects

Abstract Aristotle observes that substances have no contraries. Consider one possible role that the contrary of a substance might play, were it to exist. Just as objects serve as guarantors of the instantiation of properties, contraries of objects could serve as guarantors of the non-instantiation of properties. By first considering a reframing of deontic logic that takes ?being permitted? rather than ?being forbidden? as the default state, I develop logical tools that allow the construction of extremal models in which everything is permitted and nothing is forbidden. Transferred to quantified logic, these same tools give us a conception of antiobjects which block property instantiation. The resulting picture of antiobjects is then used as a test case to examine questions about the role of symmetry considerations in philosophical methodology.