Editing Chemical element (section)

=== Classical definitions ===
{{Main|Classical element#Hellenistic philosophy}}
[[Ancient philosophy]] posited a set of [[classical element]]s to explain observed patterns in [[nature]]. These ''elements'' originally referred to ''[[Earth (classical element)|earth]]'', ''[[Water (classical element)|water]]'', ''[[Air (classical element)|air]]'' and ''[[Fire (classical element)|fire]]'' rather than the chemical elements of modern science.

The term 'elements' (''stoicheia'') was first used by Greek philosopher [[Plato]] around 360&nbsp;BCE in his dialogue [[Timaeus (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 [[regular polyhedron|polyhedral]] [[Theory of Forms|forms]]: [[tetrahedron]] (fire), [[octahedron]] (air), [[icosahedron]] (water), and [[cube]] (earth).<ref>{{cite book|author=Plato|year=2008|orig-year=c. 360 BC|title=Timaeus|url=https://books.google.com/books?id=xSjvowNydN8C&q=Plato%20timaeus&pg=PA45|publisher=Forgotten Books|page=45|isbn=978-1-60620-018-6|access-date=9 November 2020|archive-date=14 April 2021|archive-url=https://web.archive.org/web/20210414140053/https://books.google.com/books?id=xSjvowNydN8C&q=Plato%20timaeus&pg=PA45|url-status=live}}</ref><ref>{{cite web|last=Hillar |first=M. |year=2004 |title=The Problem of the Soul in Aristotle's De anima |url=http://www.socinian.org/aristotles_de_anima.html |publisher=[[NASA]]/[[WMAP]] |access-date=10 August 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060909004214/http://www.socinian.org/aristotles_de_anima.html |archive-date=9 September 2006 }}</ref>

[[Aristotle]], {{circa|350 BCE}}, also used the term ''stoicheia'' and added a fifth element, [[Aether (classical element)|aether]], which formed the heavens. Aristotle defined an element as:

{{blockquote|Element – one of those bodies into which other bodies can decompose, and that itself is not capable of being divided into other.<ref>{{cite book|last=Partington|first=J. R.|year=1937|title=A Short History of Chemistry|location=New York|publisher=Dover Publications|isbn=978-0-486-65977-0|url-access=registration|url=https://archive.org/details/shorthistoryofch0000part_q6h4}}</ref>}}