The book aims at a comprehensive account of the relationship between Wittgenstein's Tractatus Logico-Philosophicus and Russell's philosophy as it developed between 1903 and 1918. The focus is on the central nucleus of the Tractatus, i.e., on its ontology and the picture theory of language. On Russell's side, the multiple-relation theory of judgment has been chosen as the leading theme around which the presentation of several other issues is organized. Whereas the similarity between Russell's and Wittgenstein's problems is pointed out, the deep difference between their solutions is acknowledged, in particular with reference to the opposition between objects and names on the one hand, and facts and propositions on the other.