Part I. Set-Theoretic versus Correlational Connections -- Set Relations in Social Research: Basic Concepts -- Fuzzy Sets and Fuzzy-Set Relations -- Evaluating Set Relations: Consistency and Coverage -- Part II. Calibration versus Measurement -- Why Calibrate? -- Calibrating Fuzzy Sets -- Part III. Configurations of Conditions versus "Independent" Variables -- Configurational Thinking -- Configurational Analysis Using Fuzzy Sets and Truth Tables -- Part IV. Analysis of Causal Complexity versus Analysis of Net Effects -- Limited Diversity and Counterfactual Cases coauthored with John Sonnett -- Easy versus Difficult Counterfactuals -- The Limitations of Net Effects Thinking -- Net Effects versus Configurations: An Empirical Demonstration coauthored with Peer Fiss.