Empirical controversy about the reality of cognitive illusions dissolves when viewed in the perspective of a dual-process model. System 2 'knows" some of the rules that intuitive reasoning is prone to violate, and sometimes intervenes to correct or replace erroneous intuitive judgments. Thus, errors of intuition occur when two conditions are satisfied: System 1 generates the error and System 2 fails to correct. In this view, the experiments in which cognitive illusions are "made to disappear" do so by facilitating the corrective operations of System 2.