This volume offers a new point of entry into enduring questions about how the law conceives of states and firms. Because states and firms are fictitious constructs rather than products of evolutionary biology, the law dictates which acts should be attributed to each entity, and by which actors. Those legal decisions construct firms and states by attributing identity and consequences to them. As the volume shows, these legal decisions are often products of path dependence or conceptual metaphors like “personhood” that have expanded beyond their original uses. Focusing on attribution allows the volume to consider together an array of questions about artificial entities that are usually divided into doctrinal siloes. These include questions about attribution of international legal responsibility to states and state-owned entities, transnational attribution of liabilities to firms, and attribution of identity rights to corporations. Taken together, the book highlights the artificiality of doctrines that construct firms and states, and therefore their susceptibility to change.