Originally written in October 21, 2020. Overview Classical elements typically refer to the concepts of earth, water, air, fire, and (later) aether, which were proposed to explain the nature and complexity of all matter in terms of simpler substances. Ancient cultures in Greece, Persia, Babylonia, Japan, Tibet, and India had all similar lists, sometimes referring in local languages to "air" as "wind" and the fifth element as "void". The Chinese Wu Xing system lists Wood (木 mù), Fire (火 huǒ), Earth (土 tǔ), Metal (金 jīn), and Water (水 shuǐ), though these are described more as energies or transitions rather than as types of material. These different cultures and even individual philosophers had widely varying explanations concerning their attributes and how they related to observable phenomena as well as cosmology. Sometimes these theories overlapped with mythology and were personified in deities. Some of these interpretations included atomism (the idea of ver...