Richardson's study on Carnap's early philosophy culminating in Der logische Aufbau der Welt of 1928 (henceforth Aufbau),presents a comprehensive and sustained effort at understanding it as deeply rooted in neo-Kantian patterns of thought: thus it belongs to a more recent tradition of viewing the emergence of Carnap's thought, alternative to the older approach of interpreting it against the background of empiricist themes, and well deserves to be labelled the most thoroughgoing expression this more recent tradition has been given until now.