internalist

An internalist is a philosopher or theorist who endorses internalism, a family of positions that locate certain evaluative or justificatory factors within the subject’s own mental life. In philosophy, internalists hold that justification, reasons, or knowledge depend on factors that are accessible to the subject through reflection or introspection, such as beliefs, evidence, and conscious justification. Externalists, in contrast, contend that justification can depend on factors outside the agent’s awareness, such as the reliability of cognitive processes or environmental conditions.

In epistemology, internalist positions distinguish internalist theories of justification, knowledge, and reasons from externalist ones. A core idea is that a belief is justified only if the agent has or could have access to appropriate internal evidence or reasons from within their perspective. This emphasis on internal accessibility is often presented as preserving epistemic authority and intelligibility from the agent’s point of view.

Internalism also appears in the philosophy of mind and ethics. In these areas, internalists claim that mental content, normative reasons, or motivational forces are determined by internal states rather than external contexts. Externalists challenge these claims by arguing that external factors—such as reliable processes or social or environmental influences—can ground justification, content, or reasons independently of the subject’s internal perspective.

Historically, internalism has been central to debates about knowledge, justification, and rationality since the mid-20th century, spawning a range of variants and refinements. Critics of strict internalism argue that it cannot fully account for how external conditions contribute to reliable cognition, while externalists contend that some epistemic and semantic aspects genuinely depend on factors beyond internal states.