Centuries ago when they were first invented, chairs were not meant for everybody. Mere mortals and those who were unpedigreed had to sit on chests, benches, stools, on a rock, on the ground. The person with power reserved the privilege of sitting on the chair, as it was considered an article of state and dignity, rather than ordinary use.
We've come a long way since then. Time has seen the chair evolve from thrones into virtual carved pieces, festooned with ornamentation, then into the utilitarian objects they are today. Various symbolical meanings have been heaped upon its feet through the centuries, and no other piece of furniture holds so much meaning, or perhaps so much potential for artistic interpretation.