I.- Analytical Action Theory: Breakthroughs and Deadlocks.- One Action — Two Theories? Comments on I. Thalberg.- The Contradictory Aims of Action Theory. Comments on I. Thalberg.- II.- The Concept of ‘Action’ in Sociological Analysis.- Comments on Jonathan H. Turner, ‘The Concept of “Action” in Sociological Analysis’.- Action, and Social Action. Comments on J. H. Turner.- III.- Social Action.- Analytical Action Theory as a Conceptual Basis of Social Science. Comments on Raimo Tuomela’s Paper ‘Social Action’.- We-Intentions and Process-Oriented Problems of Social Action. Comments on Raimo Tuomela’s Paper ‘Social Action’.- Reply to Seebaß and Miller.- IV.- Remarks on the Concept of Communicative Action.- Habermas on Communicative Action.- Understanding as an Aim and Aims of Understanding. Comments on Jürgen Habermas.- Critique of Habermas’s Theory of Communicative Action.- V.- Max Weber’s Distinction Between Means-End Rationality and Value-Rationality — Rationale, Scope, Difficulties.- Value-Rationality and the Distinction Between Goal-Oriented and Value-Oriented Behavior in Weber.- Value-Rationality in Weber. Comments on Johannes Weiß: ‘Max Weber’s Distinction Between Means-End Rationality and Value-Rationality — Rationale, Scope, Difficulties’.- VI.- Rationality and Valuation.- Epistemology and the Rationality of Beliefs and Valuations. Comments on Audi.- Rationality in the Light of the Epistemological Analogy. Comments on Robert Audi’s ‘Rationality and Valuation’.- Reply to Döbert and Vossenkuhl.- Index of Names.