A more thorough explanation:

Definition: Law in books refers to the laws and legal doctrines that are written down in books, such as legal reporters. This term is often used to contrast with "law in action," which refers to how laws are actually applied in real life. Scholars who study law in books often critique legal theories and doctrines, arguing that they do not accurately reflect how laws are used in practice.

One example of law in books is the United States Constitution. This document outlines the basic principles of the American legal system, but it does not necessarily reflect how those principles are applied in practice. For example, the Constitution guarantees the right to free speech, but there are many limitations on that right in practice.

Another example of law in books is the Uniform Commercial Code (UCC). This is a set of laws that govern commercial transactions in the United States. While the UCC provides a framework for how these transactions should be conducted, it does not necessarily reflect how they are actually conducted in practice.

These examples illustrate the concept of law in books because they show how legal doctrines and principles can be written down in books, but may not accurately reflect how they are applied in real life. Scholars who study law in books argue that it is important to understand both the theoretical principles of the law and how they are actually used in practice.