They see or hear things that do not exist in physical reality. But I would argue that their illusions are in fact real things. I argue that illusions are real. Note: They don't have to be true to be real. A lie is actually a real thing. That said, even from the materialist view that consciousness is an illusion produced by the brain, the illusion then has a physical reality. Indeed, even from a materialist perspective, the illusion has a physical reality in the neural connections that fire in the brain in certain ways. It has a physical reality. From the non-materialist point of view, even if there was no physical reality in the schizophrenic's illusion, his illusion has reality as a thought in consciousness! Thus, I have just proven that even an illusion is a real thing. . From the relativist's perspective, truth or falsehood depends on the viewpoint and belief of the observer. For the absolutist, truth or falsehood depends on reasonable evidence and reason. Regardless, the illusion is real, even if it is false. It is real as abstract or as neural