Legal fictions are falsehoods that the law knowingly relies on. It is the most bizarre feature of our legal system; we know something is false, and we still assume it. But why do we rely on blatant falsehood? What are the implications of doing so? Should we continue to use fictions, and, if not, what is the alternative? Legal Fictions in Private Law answers these questions in an accessible and engaging manner, looking at the history of fictions, the theory of fictions, and current fictions from a practical perspective. It proposes a solution to what to do about fictions going forward, and how to decide whether they should be accepted or rejected. It addresses the latest literature and deals with the law in detail. This book is a comprehensive analysis of legal fictions in private law and a blueprint for reform.