Hegel’s Semantics of Singular Cognitive Reference, Newton’s Methodological Rule 4 and Scientific Realism Today (*)


  • Kenneth R Westphal




Empirical investigations use empirical methods, data, and evidence. This banal observation appears to favour empiricism, especially in philosophy of science, though no rationalist ever denied their importance. Natural sciences often provide what appear to be, and are taken by scientists as, realist, causal explanations of natural phenomena, often in terms of forces or entities we do not perceive with our normal, unaided human senses. Empiricism has never been congenial to realism about such scientific posits. Bas van Fraassen’s “Constructive Empiricism” purports that realist interpretations of any “unobservables” mentioned by a scientific theory in principle always transcend whatever can be justified by that theory’s empirical adequacy, and that “explanations” are merely pragmatic, insofar as they are context‑specific to the presuppositions of whomever poses the question an explanation is to answer. Here I argue that “Constructive Empiricism” rests upon a series of flawed presumptions about natural science and about epistemology. I draw upon two main resources. One resource is the constraints upon specifically cognitive reference to particulars, first identified by Kant (and later by Evans). The second is William Harper’s (2011) brilliant re‑analysis and defense of Newton’s Principia, which shows that, and how, Newton justified his realism about gravitational force. One surprise is that Kant’s semantics of singular cognitive reference (examined in §3) directly and strongly supports Newton’s Rule 4 of scientific method (§4), which strongly supports his realism about gravi‑ tational force (summarized in §2). A further surprise is that Hegel first recognized that this semantics of singular cognitive reference directly and strongly supports Newton’s meth odological Rule 4 of experimental philosophy in ways which support Newton’s realism about gravitational force, and about distance forces generally. The textual and exegetical issues these attributions require I examine elsewhere. Here I make these important findings available to philosophers and historians of science.


(*) Invited paper