This volume is a collection of papers that advance our understanding of the metaphysics of powers — properties such as fragility and electric charge. They focus on questions concerning the metaphysics of powers that cut across any particular subject-specific ontological domain -- whether philosophy of science, philosophy of mind, ethics, epistemology – investigating the metaphysical structure of powers, the nature of the manifestation of powers, the necessity or contingency of a power’s relation to its manifestations, and powers and causation.