 From 1948 on, Brouwer also published counterexamples that are based on so-called “creating subject methods”. (He mentions in Brouwer 1948A that he has been using this method in lectures since 1927.) Their characteristic property is that they make explicit reference to the subject who carries out the mathematical constructions, to the temporal structure of its activities, and the relation of this structure to the intuitionistic notion of truth. These methods can be used to generate weak as well as strong counterexamples. (In the earlier “oscillatory number” method for generating weak counterexamples, the creating subject is not explicitly referred to.)