The book provides an overview of the recent debate on free will, discussing the implications of brain research for the problem of freedom. Additionally, the author develops his own capability-based conception of free will. Geert Keil argues that the well-understood ability to make decisions one way or another is compatible with the findings of empirical sciences, but not with the metaphysical doctrine of determinism. The revised argumentation in the new edition addresses objections and takes into account the newly published literature.