Said the chair can not be raised stool, because no stool can not be derived from the later chair. Stool, is not the first we sit today's stool, it is specifically to pedal, the equivalent of foot. It as a NES, is the later thing. This NES development to the Song Dynasty used more commonly.
In the NES, the stool grade is slightly more than the chair, the Ming and Qing period stool form Many, has the big stool, the long stool, the long bench, the round stool, the five stool, the plum blossom stool and so on.