Michael Friedman

This book introduces a new approach to the issue of radical scientific revolutions, or "paradigm-shifts," given prominence in the work of Thomas Kuhn. The book articulates a dynamical and historicized version of the conception of scientific a priori principles first developed by the philosopher Immanuel Kant. This approach defends the Enlightenment ideal of scientific objectivity and universality while simultaneously doing justice to the revolutionary changes within the sciences that have since undermined Kant's original defense of this ideal. Through a modified Kantian approach to epistemology and philosophy of science, this book opposes both Quinean naturalistic holism and the post-Kuhnian conceptual relativism that has dominated recent literature in science studies. Focussing on the development of "scientific philosophy" from Kant to Rudolf Carnap, along with the parallel developments taking place in the sciences during the same period, the author articulates a new dynamical conception of relativized a priori principles. This idea applied within the physical sciences aims to show that rational intersubjective consensus is intricately preserved across radical scientific revolutions or "paradigm-shifts and how this is achieved.

Carl Hempel introduced what he called "Craig's theorem" into the philosophy of science in a famous discussion of the "problem of theoretical terms." Beginning with Hempel's use of 'Craig's theorem," I shall bring out some of the key differences between Hempel's treatment of the "problem of theoretical terms" and Carnap's in order to illuminate the peculiar function of Wissenschaftslogik in Carnap's mature philosophy. Carnap's treatment, in particular, is fundamentally antimetaphysical—he aims to use the tools of mathematical logic to dissolve rather solve traditional philosophical problems—and it is precisely this point that is missed by his logically-minded contemporaries such as Hempel and Quine.

his paper explores the relationship between Kant’s views on the metaphysical foundations of Newtonian mathematical physics and his more general transcendental philosophy articulated in the Critique of pure reason. I argue that the relationship between the two positions is very close indeed and, in particular, that taking this relationship seriously can shed new light on the structure of the transcendental deduction of the categories as expounded in the second edition of the Critique.Author Keywords: Kant; Mathematical physics; Transcendental deduction.

The logical positivists adopted Poincare's doctrine of the conventionality of geometry and made it a key part of their philosophical interpretation of relativity theory. I argue, however, that the positivists deeply misunderstood Poincare's doctrine. For Poincare's own conception was based on the group-theoretical picture of geometry expressed in the Helmholtz-Lie solution of the space problem, and also on a hierarchical picture of the sciences according to which geometry must be presupposed be any properly physical theory. But both of this pictures are entirely incompatible with the radically new conception of space and geometry articulated in the general theory of relativity. The logical positivists's attempt to combine Poincare's conventionalism with Einstein's new theory was therefore, in the end, simply incoherent. Underlying this problem, moreover, was a fundamental philosophical difference between Poincare's and the positivists concerning the status of synthetic a priori truths.

Skeptical problems arising for Kant's version of transcendental idealism have been raised from Kant's own time to the present day. By focussing on how such problems originally arose in the wake of Kant's work, and on the first formulations of absolute idealism by Schelling, I argue that the skeptical problems in question ultimately depend on fundamental features of Kant's philosophy of natural science. As a result, Naturphilosophie and the organic conception of nature cannot easily be separated from the deep and insightful response to these problems offered by absolute idealism.

In the Introduction to the Critique of Pure Reason Kant formulates what he calls “the general problem of pure reason,” namely, “How are synthetic a priori judgements possible?” Kant explains that this general problem involves two more specific questions about particular a priori sciences: “How is pure mathematics possible?” and “How is pure natural science possible?”— where the first concerns, above all, the possibility of Euclidean geometry, and the second concerns the possibility of fundamental laws of Newtonian mechanics such as conservation of mass, inertia, and the equality of action and reaction. In answering these questions Kant develops what he calls a “transcendental” philosophical theory of our human cognitive faculties — in terms of “forms of sensible intuition” and “pure concepts” or “categories” of rational thought. These cognitive structures are taken to describe a fixed and absolutely universal rationality — common to all human beings at all times and in all places — and thereby to explain the sense in which mathematical natural science represents a model or exemplar of such rationality.

Kant's original version of transcendental philosophy took both Euclidean geometry and the Newtonian laws of motion to be synthetic a priori constitutive principles—which, from Kant's point of view, function as necessary presuppositions for applying our fundamental concepts of space, time, matter, and motion to our sensible experience of the natural world. Although Kant had very good reasons to view the principles in question as having such a constitutively a priori role, we now know, in the wake of Einstein's work, that they are not in fact a priori in the stronger sense of being fixed necessary conditions for all human experience in general, eternally valid once and for all. And it is for precisely this reason that Kant's original version of transcendental philosophy must now be either rejected entirely or radically reconceived. Most philosophy of science since Einstein has taken the former route: the dominant view in logical empiricism, for example, was that the Kantian synthetic a priori had to be rejected once and for all in the light of the general theory of relativity

Both realists and instrumentalists have found it difficult to understand (much less accept) Carnap's developed view on theoretical terms, which attempts to stake out a neutral position between realism and instrumentalism. I argue that Carnap's mature conception of a scientific theory as the conjunction of its Ramsey sentence and Carnap sentence can indeed achieve this neutral position. To see this, however, we need to see why the Newman problem raised in the context of recent work on structural realism is no problem for Carnap's conception; and we also need to locate Carnap's work on theoretical terms within his wider program of Wissenschaftslogik or the logic of science

This paper considers the evolution of the problem of scientific rationality from Kant through Carnap to Kuhn. I argue for a relativized and historicized version of the original Kantian conception of scientific a priori principles and examine the way in which these principles change and develop across revolutionary paradigm shifts. The distinctively philosophical enterprise of reflecting upon and contextualizing such principles is then seen to play a key role in making possible rational intersubjective communication between otherwise incommensurable paradigms.