Some in the social sciences argue that the same logic applies to both qualitative and quantitative methods. In A Tale of Two Cultures, Gary Goertz and James Mahoney demonstrate that these two paradigms constitute different cultures, each internally coherent yet marked by contrasting norms, practices, and toolkits. They identify and discuss major differences between these two traditions that touch nearly every aspect of social science research, including design, goals, causal effects and models, concepts and measurement, data analysis, and case selection. Although focused on the differences between qualitative and quantitative research, Goertz and Mahoney also seek to promote toleration, exchange, and learning by enabling scholars to think beyond their own culture and see an alternative scientific worldview. This book is written in an easily accessible style and features a host of real-world examples to illustrate methodological points.

Gary Goertz is professor of political science at the University of Notre Dame. His books include Social Science Concepts: A User's Guide (Princeton). James Mahoney is the Fitzgerald Professor of Economic History and professor of political science and sociology at Northwestern University. His books include Colonialism and Postcolonial Development: Spanish America in Comparative Perspective.

Preface vii

• 1. Introduction 1
• 2. Mathematical Prelude: A Selective Introduction to Logic and
• Set Theory for Social Scientists 16

• 3. Causes-of-Effects versus Effects-of-Causes 41
• 4. Causal Models 51
• 5. Asymmetry 64
• 6. Hume's Two Definitions of Cause 75

• 7. Within-Case versus Cross-Case Causal Analysis 87
• 8. Causal Mechanisms and Process Tracing 100
• 9. Counterfactuals 115

• 10. Concepts: Definitions, Indicators, and Error 127
• 11. Meaning and Measurement 139
• 12. Semantics, Statistics, and Data Transformations 150
• 13. Conceptual Opposites and Typologies 161

• 14. Case Selection and Hypothesis Testing 177
• 15. Generalizations 192
• 16. Scope 205
• 17. Conclusion 220