Like other members of the Vienna Circle, Carnap criticized traditional philosophy for its lack of clarity and precision, as is well-know from such papers as "The elimination of metaphysics through the logical analysis of language" (1932) and many other writings. In 'The Logical Syntax of Language' (1934), while still entertaining the idea that, in some sense, metaphysics is nonsense, Carnap's critique of philosophy is based on different grounds and aimed at different authors. In this book, his critique of philosophy actually takes the form of an attempt at a reconstruction of philosophy on a new basis. I shall try to examine this attempt and to show why it fails. I shall also try to show how Carnap's thought evolved on this point in later writings, in particular in "Empiricism, Semantics, and Ontology" (1950).