In order to prevent the reader from wasting his time in uselese attempts to solve supposed riddles, I warn him that the persons of the dialogue are not caricatures of living or deceased persons, much less their doubles. They are pegs to hang ideas on, and nothing else. To a certain extent this is even true for Int, who represents the position of intuitionisin. For the sake of clearness I made him speak sometimes in a somewhat more absolute way than I should have done if I had freely expressed my own opinions. The discussion is strictly limited to intuitionism; other conceptions of mathematics are touched on only in so far as they lead to objections against intuitionism. I reject any reproach for incomplete exposition of other points of view.