 In many of these cases, the line between experimental moral philosophy and its neighbors is difficult to draw: what distinguishes experimental moral philosophy from empirical moral psychology? What is the difference between experimental moral philosophy and psychology or neuroscience that investigates morality? What is the difference between experimental moral philosophy and metaethics? We might try to answer these questions by pointing to the training of the experimenters—as philosophers or as scientists—but much of the work in these areas is done by collaborative teams involving both philosophers and social scientists or neuroscientists. In addition, some philosophers work in law and psychology departments, and graduate programs increasingly offer cross-disciplinary training. Another approach would be to look at the literature with which the work engages: many psychologists (e.g., Haidt, Greene) investigating moral judgment situate their arguments within the debate between Kantians and Humeans, so engagement with the philosophical tradition might be used as a criterion to distinguish experimental moral philosophy from experimental moral psychology. All this said, an inability to sharply distinguish experimental moral philosophy from adjoining areas of investigation may not be particularly important. Experimental philosophers often point out that the disciplinary divide between philosophy and psychology is a relatively recent phenomenon; early twentieth-century writers such as William James situated themselves in both disciplines, making vital contributions to each. If there is a problem here, it is not unique to experimental moral philosophy. For example, is work on semantics that uses both linguistics and analytic philosophy best understood as linguistics or philosophy of language? These debates arise, and may be largely moot, for many research programs that cut across disciplinary boundaries.