Goodman’s predecessor in studying a constitutional system by the means of modern formal logic is, as we already said, Rudolf Carnap, who follows a very similar project as Goodman in his Der logische Aufbau der Welt (Carnap 1928). In this book Carnap investigates the example of a world built up from primitive temporal parts of the totality of experiences of a subject (the so-called “elementary experiences” or just “erlebs”) and thus faces the problem of abstraction: how can qualities, properties and their objects in the world be abstracted from our phenomenal experiences.