ABSTRACT
The distinctive twentieth-century form of positivism, 'logical empiricism' or 'logical positivism', is most closely associated with a group of philosophers active in the 1920s in Vienna, the 'Vienna Circle'. Their philosophical doctrines clearly belonged to the broad tradition of radical empiricist philosophy stemming from Hume, though they were responsible for some important innovations. Science could no longer be represented as resting upon an indubitable observational basis. Of some importance in this respect was the philosophy of linguistic analysis associated with the names of Russell, Moore and Wittgenstein in Britain. For Russell and Wittgenstein, particularly, the successful use of analytical techniques in solving problems in the theory of meaning led to a whole-scale philosophical programme known as 'logical atomism'. Analogous difficulties attend the strict form of the verification theory of meaning, and the history of logical empiricism since the twenties has consisted in a series of revisions which have progressively weakened the requirement of empirical testability.
