Abstract
Russell's multiple-relation theory of judgment, defended between 1910 and 1913, faced serious issues concerning the unity of proposition. I shall explain how the theory was motivated.
It is important to acknowledge its difference from the so-called binary theory of judgment which was adopted by Russell (who was influenced by G. E.
Moore) in his revolt against absolute idealism. Two problems of the unity of proposition are distinguished: the narrow direction and wide direction problem.
According to the later, we must be able to distinguish propositions with the same constituents but different direction of relation ("A loves B" x "B loves A"); according to the former, we must be ale to distinguish the grammatical from the ungrammatical ("A loves B" x "A B loves"). I shall explain how Russell repeatedly attempted to ensure that the multiple-relation theory can solve these two issues, and also how early Wittgenstein argued that the theory is in principle flawed in such a way that it cannot cope with them.