This is a translation of Carnap's early classic, Der Logische Aufbau der Welt and his less technical but also important article from the same period, Scheinprobleme in der Philosophie. It is no secret that Carnap abandoned the phenomenalism of the Aufbau for the physicalism of Logische Syntax der Sprache, but there is no doubt that the real message of the Aufbau—which is punctuated with the Messianic spirit of early logical positivism—is the program of "rational reconstruction" which becomes, on an inverted (...) reading and with the addition of a bias in favor of the universal descriptive and explanatory power of scientific discourse, the program of scientific reductionism. In this light, the continuities between the Aufbau and Carnap's later work completely dwarf in importance the discrepancies between these two periods of his creative output. The Aufbau remains an important book in its own right, and is not simply a detailed manifesto of a now defunct program; it is a pleasure to have it in English.—E. A. R. (shrink)