The relation between psychology and philosophy in the nineteenth century is a complicated one. On the one hand, the new science of the human mind was taken to be an example for philosophy; on the other hand, an attitude of anti-psychologism characterises philosophy at the end of the century. The tension between these two attitudes towards psychology has led to a special variant of logical realism in Britain. In the variant of logical realism defended by Stout and Moore, the central question is: How can the objectivity of judgement and thought be accounted for?. This question has its origin in Stout's psychological theories from the nineties, and has determined the direction logical realism took in Britain, in which no distinction is made between propositions and states of affairs, in which an identity theory of truth is defended, and in which true and false propositions are on an equal footing in the logical realm. A psychological approach to logical realism does not imply a form of psychologism, for these propositions are understood to be independent of the mind, and to be outside space and time.