Preface Acknowledgments Part 1: Perceiving and Conceiving 1. Primal Knowledge 2. Linguistic Follies 3. Varieties of Knowing Part 2: Knowing with Numbers 4. Measurement 5. Units and Correlates 6. Probabilities Part 3: Limited Vision 7. Social Facts 8. Vicarious Observation Part 4: Explanation 9. Empathetic Explanation 10. Causal Explanation Part 5: Policy 11. Rationality 12. Morality Summing Up Notes References Index