Neuroscientific evidence has educated us in the ways in which the brain mediates our thought and behavior and, therefore, forced us to critically examine how we conceive of free will. This volume, featuring contributions from an international and interdisciplinary group of distinguished researchers and scholars, explores how our increasing knowledge of the brain can elucidate the concept of the will and whether or to what extent it is free. It also examines how brain science can inform our normative judgments of moral and criminal responsibility for our actions. Some chapters point out the different respects in which mental disorders can compromise the will and others show how different forms of neuromodulation can reveal the neural underpinning of the mental capacities associated with the will and can restore or enhance them when they are impaired.