Short answers, pulled from the story.
Baron Hampstead declared in 1972 that no universally acceptable definition of law could ever be produced. He noted that humanity has spent millennia trying to answer exactly that question despite the ambiguity. This view suggests that the struggle to define law is persistent and that the word cannot be defined yet the attempt must never be abandoned.
The Sumerian ruler Ur-Nammu formulated the first law code by the 22nd century BC. This code consisted of casuistic statements that followed an if-then structure. It established a precedent for legal reasoning that persists today.
Theodosius II and Justinian I consolidated Roman law into the Corpus Juris Civilis between 529 and 534 AD. They reduced the mass of legal texts to one-twentieth of what existed before. This codification was heavily influenced by Greek philosophy and developed by professional jurists.
In 1297 the English Court of Common Pleas had only five judges while the highest court in France had fifty-one judges. This created a powerful and tight-knit judiciary that gave rise to a systematized process of developing common law. The difference in numbers contributed to the distinct evolution of English common law.
The proof of a crime requires two things: actus reus and mens rea. Actus reus is the act which is deemed by society to be criminal. Mens rea is the requisite malicious intent to do a criminal act. This standard applies to crimes such as murder, assault, fraud, and theft.
The first modern police force appeared in 17th-century Paris under the court of Louis XIV. The Paris Prefecture of Police claims they were the world's first uniformed policemen. This concept of a standing police force is relatively modern compared to other legal institutions.