1. The Problem of Assessment.- 1. Neurath and Quine: a puzzle of historiography.- 2. Neurath and Carnap: a misleading assimilation.- 3. Neurath and Popper: an epistemological and political polarity.- 2. Enlightenment, Neo-Marxism, Conventionalism: Towards a Critique of Cartesian Rationalism.- 1. Science as `a means for life'.- 2. Scientific holism.- 3. A conventionalistic critique of Cartesian `pseudorationalism'.- 3. Linguistic Reflexivity and `Pseudorationalism'.- 1. Methodological decision and the reflexivity of scientific language.- 2. The `physicalist' overturning of the Circle's orthodoxy.- 3. Language and reality: a metaphysical relationship.- 4. Reflexivity and the growth of science.- 5. The plurivocality and imprecision of scientific language.- 6. Methodological decision in the praxis of scientific communities.- 7. Empirical rationalism and `pseudorationalism'.- 4. Neurath versus Popper.- 1. Popper's criticism of Neurath.- 2. Neurath's reply: Protokollsatze and Basissatze.- 3. Two forms of conventionalism in conflict.- 4. `Laws of nature' and existential propositions: a criticism of the causalist and deductive model of scientific explanation.- 5. Experimenta crucis: against Popper's conception of science as an asymptotic path toward truth.- 5. The Unity of Science as a Historico-Sociological Goal: From the Primacy of Physics to the Epistemological Priority of Sociology.- 1. From `unified science' to the encyclopedic `orchestration' of scientific language.- 2. Popper's objections to the projects of Neurath and Carnap.- 3. Esprit systematique versus esprit de systeme: the encyclopedic paradigm.- 4. The epistemological priority of sociology: a criticism of the `covering-laws-model' of explanation.- 6. Strengths and Weaknesses of an Empirical Sociology.- 1. Logical empiricism and the social sciences: Hempel's analysis.- 2. Neurath's criticism of German historicism and the philosophy of values: Mill versus Dilthey and Marx versus Weber.- 3. Marxism as empirical political sociology.- 4. Sociological `pseudorationalism': the inadequacy of behaviourism and the `overmathematisation' of sociology.- 5. Causal asymmetry and the ceteris paribus clause in sociology: the limitations of functionalism and Marxism.- 6. Problems and paradoxes in social prediction: the role of reflexivity.- 7. Neurath and Hempel.- 7. Evaluation, Prescription, and Political Decision.- 1. Towards a sociology of sociology.- 2. Social theory, ethics, and law: theoretical propositions and prescriptive propositions.- 3. Happiness, utilitarianism, and social engineering.- 4. Planning for freedom: Neurath's criticism of political Platonism and the dispute with Hayek.- Conclusion: Reflexive Epistemology and Social Complexity.- List of Otto Neurath's Cited Works.- Meta-Bibliographical Note.- Author Index.