<P> Sicilian philosopher Empedocles (ca . 450 BC) proved (at least to his satisfaction) that air was a separate substance by observing that a bucket inverted in water did not become filled with water, a pocket of air remaining trapped inside . Prior to Empedocles, Greek philosophers had debated which substance was the primordial element from which everything else was made; Heraclitus championed fire, Thales supported water, and Anaximenes plumped for air . Anaximander argued that the primordial substance was not any of the known substances, but could be transformed into them, and they into each other . Empedocles was the first to propose four elements, fire, earth, air, and water . He called them the four "roots" (ῥιζὤματα, rhizōmata). </P> <P> Plato seems to have been the first to use the term "element (στοιχεῖον, stoicheion)" in reference to air, fire, earth, and water . The ancient Greek word for element, stoicheion (from stoicheo, "to line up") meant "smallest division (of a sun - dial), a syllable", as the composing unit of an alphabet it could denote a letter and the smallest unit from which a word is formed . A similar alphabetic metaphor may be the origin of the equivalent Latin word elementum (from which the English word comes), possibly based on the names of the letters' l',' m', and' n', though the validity of this idea is debated . </P> <P> In his On Generation and Corruption, Aristotle related each of the four elements to two of the four sensible qualities: </P> <Ul> <Li> Fire is both hot and dry . </Li> <Li> Air is both hot and wet (for air is like vapor, ἀτμὶς). </Li> <Li> Water is both cold and wet . </Li> <Li> Earth is both cold and dry . </Li> </Ul>

Concept of element from ancient greek to present