Unfortunately I will have to disagree strongly that what you see is based on social construction. This is the multiple levels that I alluded to earlier. On one level, you have an experience of seeing a thing. If you choose not to make it into a "thing", then you will not add any conceptual layer to it. There is no "chair" or "stool" at all. "Chair" and "stool" are concepts, they are additions/overlays to experience.