ABSTRACT
Rudolf Carnap’s first major book, The Logical Structure of the World [Der logische
Aufbau der Welt] (2003a [1928]; hereafter referred to as “Aufbau”), is a key work
for the understanding of the philosophical movement called “logical positivism”
or “logical empiricism”. Like this movement it has suffered a protracted period of
misinterpretation, but also profited from a recent renewal of interest. Once
regarded as the explicitly phenomenalist completion of Wittgenstein’s positivistic-
ally misunderstood Tractatus, it is now recognized as an extremely complex work
in its own right that continues to be the focus of intense efforts of re-evaluation
and reinterpretation. Here the aim is to abstract as much as possible from the
wealth of logical details that make up the Aufbau and to uncover the philosophi-
cal point of this work and the interpretative debates about it. 1
Carnap, language constructor: overview of the Aufbau
Carnap pursued the aim uncontroversially ascribed to the Vienna Circle –
furnishing an account of the nature of scientific knowledge adequate to the then
latest advances – and his own, more recently recognized aim – accounting for the
possibility of objective knowledge – by developing constructed languages for
scientific disciplines. Importantly, Carnap did not seek to defend the knowledge
claim of science by analysing the languages that science actually used. Over the
course of his long career, Carnap changed his mind about the nature of the
languages appropriate to the representation of scientific theories, but not about
the philosophical strategy of providing so-called rational reconstructions of the
logico-linguistic frameworks of scientific theories (in place of analysing them in
their historically given form). Their point lay in the clear exhibition of the mean-
ing and empirical basis of scientific propositions.
