In the last two decades of the nineteenth century, the semantic tradition took a turn toward ontology that would alienate those empiricists who, of course, wanted to avoid idealism, but not at the price of Platonism. A variety of issues were involved, all having to do with whether knowledge is independent of what is known: Are the objects of knowledge mindindependent? Is what we say about them mind-independent? Are their properties and relations mind-independent? These are very different questions, but the growing bias toward semantic monism tended to conflate them.

These questions elicited two separate developments widely regarded as the landmarks of a certain type of realism. The first centered around the notions of intentionality and denoting; the second around the rights and wrongs of holism. The links between these doctrines and what came to be known as “logical atomism” is the topic of the following two chapters.

The purpose of most people involved in these developments was to oppose the growing tide of German idealism and neo-Kantianism. Worthy as the project was, it was marred by an excessive reliance on psychologistic semantic categories and by a damaging confusion concerning the subject–predicate form. The former affected the semanticists' theory of empirical representation, leading to untold confusion via the so-called problem of our knowledge of the external world.