noun
A technical term in philosophy and logic, referring to a proposition that is the direct opposite of a thesis. Used in dialectical reasoning.
ヘーゲルの弁証法では、テーゼに対して反定立が提示される。
In Hegel's dialectic, an antithesis is presented against the thesis.
Compound of 反 (anti-) and 定立 (thesis, from 定 'fixed' + 立 'establish'). The term was likely coined in Japanese to translate the Western philosophical concept of antithesis.