Geocentric model that both Venus and Mercury went around the Sun rather than the Earth, but this is no longer accepted. Martianus Capella definitely put Mercury and Venus in orbit around the Sun. Aristarchus of Samos was the most radical. He wrote a work, which has not survived, on heliocentrism, saying that the Sun was at the center of the universe, while the Earth and other planets revolved around it. His theory was not popular, and he had one named follower, Seleucus of Seleucia. In 1543, the geocentric system met its first serious challenge with the publication of Copernicus' "De revolutionibus orbium
Singular term pronouns (e.g. "she"), demonstrative pronouns (e.g. "this"), etc. Historically, various definitions for "singular term" have been offered: Singular term A singular term is a paradigmatic referring device in a language. Singular terms are of philosophical importance for philosophers of language, because they "refer" to things in the world, and the ability of words to refer calls for scrutiny. Singular terms are defined as expressions that purport to denote or designate particular individual people, places, or other objects. They contrast with "general terms" (such as "car" or "chair") which can apply to more than one thing. There are various kinds of