This book concerns the modal and hyperintensional foundations of ethics. The book provides three metaphysical frameworks in which to examine the nature of ethical value, obligation, cognition, and consciousness. The first framework is an algebraic semantics, and provides support for the claim that truths about modality are metaphysically fundamental. The second framework is a multi-dimensional hyperintensional semantics, and is shown to provide a natural setting in which to address issues both in decision theory and which concern intentional action. The third (...) framework is a hyperintensional property theory. The framework enables properties -- such as intrinsic goodness -- to be identical to physical properties, while demonstrating how they are yet relatively discernible; and it is flexible enough to define relational notions of goodness, such as the property of being a good book and of something being good-for an agent. Within the foregoing metaphysical frameworks, the book examines the semantics of deontic modality; the relations between values and moral obligations; the role of intuition, abductive methodology, and virtue in accounting for moral knowledge; the modal profile of ethical intuition; the nature of the emotions; the source of the indeterminacy evinced by disagreements concerning properties of taste and of morals; the tenability of moral scepticism; and the modal profile of ethical cognition. (shrink)