Widespread interest in Frege’s general philosophical writings is, relatively speaking, a fairly recent phenomenon. But it is only very recently that his philosophy of mathematics has begun to attract the attention it now enjoys. This interest has been elicited by the discovery of the remarkable mathematical properties of Frege’s contextual definition of number and of the unique character of his proposals for a theory of the real numbers.

This collection of essays addresses three main developments in recent work on Frege’s philosophy of mathematics: the emerging interest in the intellectual background to his logicism; the rediscovery of Frege’s theorem; and the reevaluation of the mathematical content of The Basic Laws of Arithmetic. Each essay attempts a sympathetic, if not uncritical, reconstruction, evaluation, or extension of a facet of Frege’s theory of arithmetic. Together they form an accessible and authoritative introduction to aspects of Frege’s thought that have, until now, been largely missed by the philosophical community.

A renowned philosopher’s final work, illuminating how the logical empiricist tradition has failed to appreciate the role of actual experiments in forming its philosophy of science.

The logical empiricist treatment of physics dominated twentieth-century philosophy of science. But the logical empiricist tradition, for all it accomplished, does not do justice to the way in which empirical evidence functions in modern physics.

In his final work, the late philosopher of science William Demopoulos contends that philosophers have failed to provide an adequate epistemology of science because they have failed to appreciate the tightly woven character of theory and evidence. As a consequence, theory comes apart from evidence. This trouble is nowhere more evident than in theorizing about particle and quantum physics. Arguing that we must consider actual experiments as they have unfolded across history, Demopoulos provides a new epistemology of theories and evidence, albeit one that stands on the shoulders of giants.

On Theories finds clarity in Isaac Newton’s suspicion of mere “hypotheses.” Newton’s methodology lies in the background of Jean Perrin’s experimental investigations of molecular reality and of the subatomic investigations of J. J. Thomson and Robert Millikan. Demopoulos extends this account to offer novel insights into the distinctive nature of quantum reality, where a logico-mathematical reconstruction of Bohrian complementarity meets John Stewart Bell’s empirical analysis of Einstein’s “local realism.” On Theories ultimately provides a new interpretation of quantum probabilities as themselves objectively representing empirical reality.