In the philosophy of perception, critical realism is the theory that some of our sense-data (for example, those of primary qualities) can and do accurately represent external objects, properties, and events, while other of our sense-data (for example, those of secondary qualities and perceptual illusions) do not accurately represent any external objects, properties, and events.
René Descartes developed the theory that, since we could not definitely prove anything we experienced, the only thing which is sure to exist is our mind.
The American critical realist movement was a response both to direct realism, as well as to idealism and pragmatism.
[2] One innovation was that these mediators are not ideas (British empiricism), but properties, essences, or "character complexes".
Major figures included Samuel Alexander, John Cook Wilson, H. A. Prichard, H. H. Price, and C. D. Broad.