Introduction: Three Simple Truths About Revenge and Forgiveness.

1 Putting Vengeance and Forgiveness Back into Human Nature.

2 Revenge Is a Problem: Counting the Costs.

3 Revenge Is a Solution: Three Evolutionary Hypotheses.

4 The Retribution Solution: The Evidence for Adaptation.

5 Family, Friendship, and the Functions of Forgiveness.

6 The Forgiveness Instinct.

7 The Forgiving Brain.

8 "To Promote and to Maintain Friendly Relations": Making Forgiveness Happen.

9 From Neurons to Nations.

10 Divine Forgiveness and Righteous Revenge.

11 Homo ignoscens.

Notes.

Bibliography.

The Author.

Index.