 Realization, which has figured prominently in recent versions of non-reductive physicalism may seem too weak a relation to support a reduction claim, but nonetheless strong enough to guarantee ontological unity on the token level that underlies physicalism. Realization can be described in terms of dependence; e.g., for a particular physiological event-type to realize pain is for it to be such that in virtue of its physiological organization, its instances play the pain-role. This obviously suits the (role-) functionalist interpretation of higher-level properties; these higher-level properties are realized by lower level ones in the sense that instances of the latter play the role of the former in virtue of their physical organization.