<P> The concept of an "element" as an undivisible substance has developed through three major historical phases: Classical definitions (such as those of the ancient Greeks), chemical definitions, and atomic definitions . </P> <P> Ancient philosophy posited a set of classical elements to explain observed patterns in nature . These elements originally referred to earth, water, air and fire rather than the chemical elements of modern science . </P> <P> The term' elements' (stoicheia) was first used by the Greek philosopher Plato in about 360 BCE in his dialogue Timaeus, which includes a discussion of the composition of inorganic and organic bodies and is a speculative treatise on chemistry . Plato believed the elements introduced a century earlier by Empedocles were composed of small polyhedral forms: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth). </P> <P> Aristotle, c. 350 BCE, also used the term stoicheia and added a fifth element called aether, which formed the heavens . Aristotle defined an element as: </P>

Who used the term element for the first time