Thirty years after the publication of Thomas Kuhn’s The Structure of Scientific Revolutions, sharp disagreement persists concerning the implications of Kuhn’s "historicist" challenge to empiricism. I discuss the historicist movement over the past thirty years, and the extent to which the discourse between two branches of the historical school has been influenced by tacit assumptions shared with Rudolf Carnap’s empiricism. I begin with an examination of Carnap’s logicism --his logic of science-- and his 1960 correspondence with Kuhn. I focus on (...) problems in the analysis applied to the unit of metascientific study or appraisal, arguing for a reassessment of historicist treatment of the internal/external distinction and historiographic meta-methodology. The critique of objectivism and relativism that eventuates from this re-assessment is a double-edged blade, undercutting both objectivist and relativist treatments of cognitive evaluation and scientific change. I use it to cut across an otherwise diverse group of historicist-influenced writers, including Imre Lakatos, Larry Laudan, H. M. Collins, Stephen Stich. I. Introduction.. (shrink)