   Russell’s 1903 account of propositions as complexes of entities was in many ways in keeping with his views as the nature of complexes and facts during the core logical atomist period of 1911–1925. In particular, at both stages he would regard the simple truth that an individual a stands in the simple relation R to an individual b as a complex consisting of the individuals a and b and the relation R. However, there are a number of positions Russell held in 1903 that were abandoned in this later period; some of the more important were these: (1) in 1903, Russell was committed to a special kind of propositional constituent called a “denoting concept”, involved in descriptive and quantified propositions; (2) in 1903, Russell believed that there was such a complex, i.e., a proposition, consisting of a, b and R even when it is not true that a bears relation R to b, and (3) in 1903, Russell believed in the reality of classes, understood as aggregate objects, which could be constituents of propositions. In each case, it is worth, at least briefly, discussing Russell’s change of heart.