Internalists

Internalists are proponents of internalism, a family of theories in philosophy that hold that certain properties of mental states—such as justification, reasons, belief formation, or content—depend on internal factors accessible to the subject. In epistemology, internalism asserts that what justifies a belief and the mental evidence available to the believer must be determined by internal cognitive states rather than by external factors alone. Externalists counter that justification can depend on features outside the agent's mental life, such as reliability or causal connections to the world.

In other domains, internalism appears in philosophy of mind and language, where internalist accounts of mental content or meaning contend that the content of a thought is fixed by internal conditions rather than by the environment. In moral philosophy, moral internalists argue that reasons for action and moral motivation are grounded in the agent's internal commitments, desires, or values; externalists contend that reasons can depend on external obligations or social facts. Debates between internalists and externalists touch on issues of cognitive access, practical rationality, and epistemic closure. Contemporary discussions often explore refined forms of internalism, including contextualist and humble internalist positions, as well as hybrid theories that seek common ground between internal accessibility and external determinants. See also externalism, epistemology, moral psychology, philosophy of mind, and content theory.