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.