 At this crucial point of the Aufbau (§§125–7), the ascent from two to three dimensions, where Carnap stops spelling out the steps in detail, he also suspends the explicit definition applied up to there, and instead resorts to an informally described optimization approach, whereby certain fairly obvious desiderata (continuity of motions, temporal continuity of objects and processes, etc.) are to be maximized subject to certain (again fairly obvious) constraints (see the supplement  Aufbau (Section 3)  for further details). The construction of the physical realm and the further realms on its basis (the heteropsychological, social, cultural, and value realms) are sketched very sparsely. The book ends with a final section discussing some philosophical consequences of the constitution system, addressing (though only obliquely, and hardly by name) both phenomenology and various forms of realism.