The introduction discusses the development and substance of transitional justice theory. It shows the main assumptions embedded in this theory, which posits a direct and necessary link between criminal trials for past atrocities and post-authoritarian transitions to democracy. In a nutshell, the theory assumes that better trials lead to better democracy. Transitional justice theory has three main presuppositions. First, the theory assumes that criminal trials have a deterrent effect that prevents new authoritarian atrocities. Second, it asserts that trials offer democratizing lessons in history. Finally, it assumes that trials for past atrocities are necessarily and inherently democratizing because they promote liberal due process rights. The German case calls into question all three of these assumptions. In western Germany, liberalization occurred, but mainly as a way to avoid justice for Nazi crimes. And in the east, fair trials led not to democracy, but to a new authoritarianism.