alien?:) *** The Elements Plato assumes that the minute particle of each element had a special geometric shape: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth). Tetrahedron (fire) Octahedron (air) Icosahedron (water) Cube (earth) The Timaeus conjectures on the composition of the four elements which the ancient Greeks Platonic solid