 According to Brouwer every real number is represented by a choice sequence, and the choice sequences enabled him to capture the intuitionistic continuum via the controversial continuity axioms. Brouwer first spoke of choice sequences in his inaugural address (Brouwer 1912), but at that time he did not yet treat them as a fundamental part of his mathematics. Gradually they became more important and from 1918 on Brouwer started to use them in a way explained in the next section. 