Possibilitycan

Possibilitycan is a theoretical construct in philosophy of modality and decision theory that captures the subset of possibilities that are both true possibilities and within an agent's power to realize or influence. It blends modal possibility with agency, distinguishing between what could possibly occur and what an agent could causally bring about given resources, knowledge, and constraints. Etymology is a portmanteau of possibility and can, signaling both feasibility and agency.

In formal terms, Possibilitycan(A, φ) holds when there exists a course of action available to agent A under which φ would obtain, taking into account constraints such as physical feasibility, knowledge, time, and other relevant factors. It thus refines ordinary possibility by incorporating actionability. For example, it is possible for a patient to recover if given the right treatment, but it is not possible for a bystander to enforce that recovery without access to treatment. Conversely, it is possible for the sun to rise tomorrow whether or not any agent acts, but Possibilitycan would be false for an agent who cannot influence sunrise.

Applications include AI planning and risk assessment, where systems must distinguish outcomes that are merely possible from those that agents can realize. In ethics, it bears on discussions of responsibility by focusing on outcomes within an agent's control. Critics note that Possibilitycan relies on context-sensitive assessments of capability and can be difficult to operationalize, especially in complex environments.

See also Modal logic; possible world semantics; capability theory; agency.