Full Idea
The intuitionism of Poincaré, Brouwer, Weyl and others holds that classes are invented, and accepts reference to abstract entities only if they are constructed from pre-specified ingredients.
Gist of Idea
Intuitionism says classes are invented, and abstract entities are constructed from specified ingredients
Source
Willard Quine (On What There Is [1948], p.14)
Book Reference
Quine,Willard: 'From a Logical Point of View' [Harper and Row 1963], p.14