incommensurability

This chapter examines how dominant modernist and colonial world-system logics shape both the understanding and practice of social movements, emphasizing the necessity of disrupting these hegemonic discourses to enable revolutionary change. It highlights the incommensurability between the prevailing order's values and those of marginalized actors, particularly the 'colonial other,' and argues for decolonizing thought to recognize alternative worldviews and revolutionary practices that challenge exclusionary power structures.

This introductory essay by Ian Hacking reflects on the enduring significance and context of Thomas Kuhn's 'The Structure of Scientific Revolutions,' emphasizing its impact on the philosophy and history of science. It outlines Kuhn's concept of scientific revolutions as structured processes involving normal science, anomalies, crises, and paradigm shifts, and situates the book historically within the scientific and geopolitical climate of 1962. The essay also contrasts Kuhn's notion of scientific revolutions with earlier ideas, such as Kant's and the scientific revolutions of the seventeenth and nineteenth centuries, highlighting Kuhn's unique contribution to understanding scientific progress.

This introductory chapter challenges the traditional, cumulative view of scientific progress by emphasizing the importance of historical context in understanding science. Kuhn argues that science is not merely a steady accumulation of facts and theories but involves paradigm-dependent practices and beliefs that shape normal science and occasional revolutionary shifts. The chapter introduces the idea that scientific communities operate within conceptual frameworks that guide research until anomalies provoke paradigm shifts, termed scientific revolutions.

This chapter explores how scientific revolutions entail fundamental changes in scientists' perception of the world, akin to shifts in gestalt vision, where familiar objects are seen differently due to new paradigms. It argues that scientific observation is paradigm-dependent, meaning that what scientists see and how they interpret data is shaped by their conceptual framework, and that paradigm shifts cause scientists to perceive previously unnoticed phenomena. Historical examples, such as Herschel's discovery of Uranus, illustrate how changes in scientific paradigms alter both perception and the classification of observed phenomena.

This chapter analyzes the process by which scientific revolutions resolve, focusing on how new paradigms replace old ones through the conversion of the scientific community. Kuhn critiques traditional views of verification and falsification, arguing that paradigm shifts involve complex competition between incommensurable worldviews rather than straightforward empirical testing. He emphasizes that the acceptance of a new paradigm depends on its comparative problem-solving ability and the scientific community's gradual shift in perspective, rather than definitive proof or neutral language.

In this 1969 postscript to The Structure of Scientific Revolutions, Kuhn reflects on critiques and clarifies key concepts, especially the notion of 'paradigm.' He distinguishes between the sociological sense of paradigm as a shared scientific community's beliefs and the philosophical sense as exemplary puzzle-solutions guiding normal science. Kuhn addresses misunderstandings about subjectivity and relativism in science, proposes viewing incommensurable scientific theories as different language communities, and briefly considers the book's applicability beyond science.

This chapter elaborates on the concept of incommensurability between successive scientific theories, emphasizing that scientists debating theory choice often use the same vocabulary differently, leading to partial communication and the necessity of persuasion rather than proof. Kuhn explains that scientific revolutions involve changes in fundamental similarity relations learned from exemplars, causing shifts in classification and language use that complicate communication. He further discusses how translation between language communities can facilitate understanding, persuasion, and sometimes conversion, though these processes are neither straightforward nor guaranteed.