Not Rivals
Idealism and materialism are not rival descriptions of reality. They are failed attempts to absolutize one side of a necessary distinction. Each takes something real and then commits a category error by inflating it into total ontology.
Materialism says what really exists is matter, and experience somehow “comes out of it.” This fails because “matter” is already a theoretical construct inside experience. Physics does not describe noumenal stuff; it describes mathematically constrained regularities of appearance. The deeper physics goes, the less “matter” looks like anything material at all. Fields, probabilities, symmetries, operators. Materialism survives only by quietly redefining matter as “whatever physics talks about,” which makes it vacuous. It explains nothing about why there is experience rather than none.
Idealism flips the error. It says what really exists is experience, and objects are unnecessary add-ons. This fails because it confuses conditions of access with conditions of existence. Yes, all knowledge is mediated by experience. No, that does not mean existence depends on experience. Idealism smuggles the human point of view into the foundations of the cosmos and then calls it radical. It cannot account for deep time, causal independence, or the fact that reality routinely surprises, resists, and injures us.
Both positions commit the same mistake by trying try to turn an epistemic truth into an ontological monopoly. What actually holds is more austere and less flattering. There is a reality that is not exhausted by how it appears, and there is experience as the way that reality is accessed by certain biological systems. Experience is real. The world is real. Neither reduces to the other.
Kant already nailed the structure. Empirical realism without transcendental arrogance. Metzinger sharpens it saying that there is no self as an entity, but there is a self-model operating in a world that does not care about that model. “Mind” and “matter” are bad primitives but it would be wrong to conclude that only experience remains. Removing bad concepts does not entitle you to crown the remainder as absolute.
So what is “right”? Not idealism. Not materialism. Ontological realism paired with epistemic humility. Reality exists independently. Experience is how it shows up for systems like us. The relation is asymmetric, not interchangeable. The moon exists whether or not it is experienced. But the moon-for-John exists only in experience. Confusing those two is the entire problem.
Reality does not need a witness, but every witness needs reality.