The History of Russell’s Concepts ‘Sense-data’ and ‘Knowledge by Acquaintan¬ce’

Two concepts of utmost importancc for the analytic philosophy of the twentieth century, »sense-data« and »knowledge by acquaintance«, were introduced byBertrand Russell under the influence of two idealist philosophers: Francis Herbert Bradley and Alexius Meinong. In this paper we will trace the cxact history of theirintroduction. We will see that betwecn 1896 and 1898, Russell had a well-elaborated theory of »sense-Jata«, which he abandoned after his analytic turn of the summer of 1898. However, following his new turn of August 1900 - after he bccame acquainted with the works of Giuseppe Peano and later of Gottlob Fregc - Russell gradually Jeveloped a new. second theory of sense-data. He reintroduced the term »sense-data« in 1911 with the crucial help of his friend George Edward Moore. In parallel, Russell also introduced the epistemological term »knowledge by acquaintance«, which came to designate, above all, the grasping of scnse-data.