Gideon Yaffe presents a ground-breaking work which demonstrates the importance of philosophy of action for the law. Many people are serving sentences not for completing crimes, but for trying to. So the law governing attempted crimes is of practical as well as theoretical importance. Questions arising in the adjudication of attempts intersect with questions in the philosophy of action, such as what intention a person must have, if any, and what a person must do, ifanything, to be trying to act. Yaffe offers solutions to the difficult problems courts face in the adjudication of attempted crimes. He argues that the problems courts face admit of principled solution through reflection either on what it is to try to do something; or on what evidence is requiredfor someone to be shown to have tried to do something; or on what sentence for an attempt is fair given the close relation between attempts and completions. The book argues that to try to do something is to be committed by ones intention to each of the components of success and to be guided by those commitments. Recognizing the implications of this simple and plausible position helps us to identify principled grounds on which the courts ought to distinguish between defendants charged withattempted crimes.