Epistemological idealism

Epistemological idealism is a subjectivist position in epistemology that holds that what one knows about an object exists only in one's mind. It is opposed to epistemological realism.

Epistemological idealism can mean one of two unrelated positions:

• Everything we experience and know is of a mental nature, sense data in philosophical jargon. Although it is sometimes employed to argue in favor of metaphysical idealism, in principle epistemological idealism makes no claim about whether or not sense data are grounded in reality. As such, it is a container for both indirect realism and idealism.
• Knowledge is of a mental nature. That is: ideas, concepts and propositions (and perhaps logic) exist only in the mind and have no extra-mental existence. See psychologism.