Newton, quantum theory and reality.

Anthony Sudbery

There are two broad opposing classes of attitudes to reality (realist vs idealist, material vs mental) with corresponding attitudes to knowledge (objective vs subjective, scientific vs romantic). I argue that these attitudes can be compatible, and that quantum theory requires us to adopt both of them.

Arthur I. Fine, Mario Bunge

William Demopoulos

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.

Bernard d’Espagnat

Rienk H. Vermij

Discoveries in the field of energy and electromagnetism were important theoretical innovations, but they also figured in more metaphysical debates about the nature of reality. The Scientific Revolution of the seventeenth century included not least a radical new vision of natural reality. The notion that knowledge of elementary building blocks meant knowledge of reality as such was in essence the ideal of seventeenth-century mechanical philosophy, but in the twentieth century it turned out to have lost none of its power. Research into radiation and the particles it emitted developed rapidly into a fully fledged field of research, for which all kinds of new methods and instruments were invented. To understand phenomena in the depths of space, Newton's theory is in many cases inadequate and the theory of relativity comes into play. For the general public, quantum mechanics was embodied most of all by what is known as Heisenberg's uncertainty principle.

Oreste Piccioni, Werner A. W. Mehlhop