Air. Air is one of the four classical elements in ancient Greek philosophy and in Western alchemy.
   According to Plato, it is associated with the octahedron; air is considered to be both hot and wet. The ancient Greeks used two words for air: aer meant the dim lower atmosphere, and aether meant the bright upper atmosphere above the clouds.
   Plato, for instance writes that So it is with air: there is the brightest variety which we call aether, the muddiest which we call mist and darkness, and other kinds for which we have no name. Among the early Greek Pre-Socratic philosophers, Anaximenes named air as the arche.
   A similar belief was attributed by some ancient sources to Diogenes Apolloniates, who also linked air with intelligence and soul, but other sources claim that his arche was a substance between air and fire. Aristophanes parodied such teachings in his play The Clouds by putting a prayer to air in the mouth of Socrates.
   Air was one of many archai proposed by the Pre-socratics, most of whom tried to reduce all things to a single substance. However, Empedocles of Acragas selected four archai for his four roots: Air, fire, water, and earth. Ancient and modern opinions differ as to whether he identified air by the divine name Hera, Aidoneus or even Zeus. Empedocles' roots became the four classical elements of Greek philosophy. Plato took over the four elements of Empedocles. In the
Wikipedia ...