Earth is one of the four classical elements in ancient Greek philosophy and science. It was commonly associated with qualities of heaviness, matter and the terrestrial world. Due to the hero cults, and chthonic underworld deities, the element of earth is also associated with the sensual aspects of both life and death in later occultism.
Empedocles of Acragas (c. 495 – c. 435 BCE) proposed four archai by which to understand the cosmos: fire, air, water, and earth. Plato (427 – 347 BCE) believed the elements were geometric forms (the platonic solids) and he assigned the cube to the element of earth in his dialogue Timaeus. Aristotle, (384–322 BCE), believed earth was the heaviest element, and his theory of natural place suggested that any earth–laden substances, would fall quickly, straight down, toward the center of the cosmos. [source: Wikipedia]