We spend a great deal of time learning our vocations and avocations as we work at jobs, participate in home life, and take part in civic activities and politics. In doing so, we engage in practices that consist of complex bodies of norms. These practices themselves are bodies of knowledge-often acquired from others-about what we take to be good ways or right ways to do certain things. As we learn how to solve problems and act on this knowledge, the practice itself changes. In Norms and Practices, James D. Wallace shows that norms of all kinds, including ethical norms, are intensely social constructs learned through constant interaction with others. Wallace suggests that ethical norms have long been misunderstood as practice-independent prescriptions for behavior; he regards them instead as items of practical knowledge that are constituents of practices. We are given the luxury of learning from others' mistakes and successes, often in a very informal way. Such lessons from collective or individual experience often carry more weight than do pronouncements from an external source. Wallace shows that practices and norms, including ethical norms within such spheres as biomedical research, family life, and politics, continually change as practitioners face novel problems.