As a leading member of the Vienna Circle, Rudolph Carnap's aim was to bring about a "unified science" by applying a method of logical analysis to the empirical data of all the sciences. This work, first published in English in 1934, endeavors to work out a way in which the observation statements required for verification are not private to the observer. The work shows the strong influence of Wittgenstein, Russell, and Frege.

Rudolf Carnap

1. The Heterogeneity of Science 2. Languages 3. Protocol Language 4. The Physical Language as an Intersubjective Language 5. The Physical Language as an Universal Language 6. Protocol Language as a Part of Physical Language 7. Unified Science in Physical Language