to suppose (something) beforehand, usu without proof or justification
to require (something) to exist or be the case in order that something else may exist or be true or valid
A creation presupposes a creator
presupposition /ˌpreesupəʹzish(ə)n/ noun
[Middle English presupposen via French from late Latin praesupponere, from prae- + supponere: see suppose]