 Becker, following Husserl, has described its meaning very clearly. For him negation is something thoroughly positive, viz., the intention of a contradiction contained in the original intention. The proposition “\(C\) is not rational”, therefore, signifies the expectation that one can derive a contradiction from the assumption [Annahme] that \(C\) is rational. It is important to note that the negation of a proposition always refers to a proof procedure which leads to the contradiction, even if the original proposition mentions no proof procedure. (Heyting 1931: 113 [Benacerraf &amp; Putnam 1983: 59])