This article attempts to develop a rational reconstruction of Kuhn's epistemological relativism which effectively defends it against an influential line of criticism in the work of Shapere and Scheffler. Against the latter's reading of Kuhn, it is argued (1) that it is the incommensurability of scientific problems, data, and standards, not that of scientific meanings which primarily grounds the relativism argument; and (2) that Kuhnian incommensurability is compatible with far greater epistemological continuity from one theory to another than is implied (...) by the criticisms in question. The reconstruction of Kuhn is then used to show that while it constitutes a provocative form of relativism, it can also plausibly account for the sense in which scientific development is rational, involves standards external to particular paradigms, and exhibits progress of a sort. Finally, the article attempts to develop an adequate critical perspective on Kuhn's relativism by distinguishing a ?short?run? from a ?long?run? relativism, and a relativism concerning scientific knowledge from one concerning scientific rationality in Kuhn; the challenge each poses to positi?vist philosophy of science is distinguished and separately evaluated. (shrink)

Through a study of a sophisticated contemporary scientific experiment, it is shown how and why use of the term 'observation' in reference to that experiment departs from ordinary and philosophical usages which associate observation epistemically with perception. The role of "background information" is examined, and general conclusions are arrived at regarding the use of descriptive language in and in talking about science. These conclusions bring out the reasoning by which science builds on what it has learned, and, further, how that (...) process of building consists not only in adding to our substantive knowledge, but also in increasing our ability to learn about nature, by extending our ability to observe it in new ways. The argument of this paper is thus a step toward understanding how it is that all our knowledge of nature rests on observation. (shrink)