(philosophy) the doctrine that knowledge is acquired primarily by intuition WordNet 3.0 & Open English WordNet

In the philosophy of mathematics, intuitionism, or neointuitionism, is an approach where mathematics is considered to be purely the result of the constructive mental activity of humans rather than the discovery of fundamental principles claimed to exist in an objective reality. Wikipedia

approach in philosophy of mathematics and logic Wikidata

An approach to mathematics/logic which avoids proof by contradiction, and which requires that, in order to prove that something exists, one must construct it. Wiktionary

Approach to mathematics which avoids proof by contradiction. Wiktionary (translation)