Philosophy of Action is based on the lectures given in the Royal Institute of Philosophy's annual London lecture series 2015-16. This volume brings together an internationally distinguished team of lecturers. As befits the theme itself, a wide range of topics relating to action are covered. These include the nature of action itself and its relation to knowledge-how. There are a number of papers on issues relating to freedom and responsibility, and also to the relation between action and causation. Other papers consider the notion of planning in relation to agency, and the connection between agency and practical abilities. And there are also considerations of virtue and ethical concepts as applied to the notion of action. The papers collected here will testify to the liveliness of discussions of action in contemporary philosophy, and will also demonstrate the way many ancient conceptions of action are being developed in contemporary philosophical thought.