I am having difficulty understanding your point. Please feel free to clarify. To me "noumen" means mental or "thought" derived part. Yeah the couch looks like

I am having difficulty understanding your point. Please feel free to clarify. To me "noumen" means mental or "thought" derived part. Yeah the couch looks like a zebra. The idea it looks like a zebra is not wrong. However the conclusion that it therefore is a zebra is wrong. It is a visual misidentification. What distinguishes this from an illusion? We are not looking at true forms versus reality. We are looking at perceived form versus reality. When perceived form diverges from reality that seems like an illusion to me. Maybe you could call it something else, a mistake. What's the point here that you are trying to make?