These essays apply the core conceptual innovation underlying Frege's theory of number to the general analysis of theoretical knowledge.

William Demopoulos is Professor of Philosophy at the University of Western Ontario. He has edited many volumes on foundational and philosophical issues arising in the sciences, including Physical Theory and its Interpretation (with Itamar Pitowsky, 2006) and Frege's Philosophy of Mathematics (1995).

Preface; Introduction; 1. Frege's analysis of arithmetical knowledge; 2. Carnap's thesis, on extending 'empiricism, semantics and ontology' to the realism-instrumentalism controversy; 3. Carnap's analysis of realism; 4. Bertrand Russell's The Analysis of Matter: its historical context and contemporary interest with Michael Friedman; 5. On the rational reconstruction of our theoretical knowledge; 6. Three views of theoretical knowledge; 7. Frege and the rigorization of analysis; 8. The philosophical basis of our knowledge of number; 9. The 1910 Principia's theory of functions and classes; 10. Ramsey's extensional propositional functions.