Simple (philosophy)

In contemporary mereology, a simple or indivisible monomere (in mereology, not in chemistry) is any thing that has no proper parts. Sometimes the term "atom" is used, although in recent years[when?] the term "simple" has become the standard.

Simples are to be contrasted with atomless gunk (where something is "gunky" if it is such that every proper part has a further proper part; a potential omnidivisible). Necessarily, given the definitions, everything is either composed of simples, gunk or a mixture of the two. Classical mereology is consistent with both the existence of gunk and either finite or infinite simples (see Hodges and Lewis 1968).