Intuitionism sacrificed large parts of mathematics in exchange for the soothing reassurance that what remained was justified by our ‘primordial intuition’ (Urintuition;. But intuition is subjective, and not intersubjective enough to prevent intuitionists form differing about what their ‘primordial intuitions’ should enshirine as the basis of mathematics.
(Kalmar, 1967, page 190).
Thus the positive thesis of intuitionism does not provide a certain foundation for even a subset of mathematical knowledge. This criticism extends to other forms of constructivism which also claim to base constructive mathematical truth on a foundation of self-evident constructivist assumptions.
The negative thesis of intuitionism (and of constructivism, when it is embraced), leads to the unwarranted rejection of accepted mathematical knowledge, on the grounds that it is unintelligible. But classical mathematics is intelligible. It differs from constructivist mathematics largely in the assumptions on which it is based. Thus constructivism is guilty of what is analogous to a Type I Error in statistics, namely the rejection of valid knowledge.