 The two acts of intuitionism do not in themselves exclude a psychological interpretation of mathematics. Although Brouwer only occasionally addressed this point, it is clear from his writings that he did consider intuitionism to be independent of psychology. Brouwer’s introduction of the Creating Subject (Brouwer 1948) as an idealized mind in which mathematics takes place already abstracts away from inessential aspects of human reasoning such as limitations of space and time and the possibility of faulty arguments. Thus the intersubjectivity problem, which asks for an explanation of the fact that human beings are able to communicate, ceases to exist, as there exists only one Creating Subject. In the literature, also the name Creative Subject is used for Creating Subject, but here Brouwer’s terminology is used. In (Niekus 2010), it is argued that Brouwer’s Creating Subject does not involve an idealized mathematician. For a phenomenological analysis of the Creating Subject as a transcendental subject in the sense of Husserl see (van Atten 2007). 