ABSTRACT
This chapter explains that model-theory is an important instrument for philosophical analysis. The absence of model-theory cost Whitehead an efficient tool for analyzing and characterizing the structural features of relational abstractions. The chapter sketches such a model-theoretic approach, closely approximating Whitehead's actual analysis. It argues that model-theoretic approaches come with an implicit, but essentially "built-in" implicit realist "metaphysics". The chapter also explains Whitehead's philosophy of science and nature, informed now by the authors' account of his relationalism in the context of the quantum of explanation and the intricate algebra of negative prehension. It looks at two attempts to do an "end-around" on the careful metaphysics of nature. The chapter notes how Whitehead's radical empiricism is pervasive in all of his works. It finally explains Whitehead's scientific realism with his already noted Jamesian radical empiricism. Whitehead entered into the philosophy of science from the position of a working scientist.
