We will study the intersection between science and philosophy in defining and understanding free will, with the aim of learning the latest science on the nature and existence of free will and how to critically approach philosophical uses of it. Students will not only learn about the relevant elements of brain science, but also how to identify common philosophical fallacies in reasoning about free will, and the real-world application of the analysis of free will in diverse fields, from law to medical ethics. Course topics: The varieties of free will and the differences among them; identifying causes and the role of personal identity in making decisions (and what the latest brain science has to say about both); the nature and purpose of assigning responsibility to personal agents (in law, ethics, and daily life); the difference between determinism and fatalism, and the importance of addressing both personal and genetic-environmental causes of decisions when thinking about social, political, legal, and moral systems.