civile ("citizen law", originally ius civile Quiritium) was the body of common laws that applied to Roman citizens and the Praetores Urbani, the individuals who had jurisdiction over cases involving citizens. The ius gentium ("law of peoples") was the body of common laws that applied to foreigners, and their dealings with Roman citizens. The Praetores Peregrini were the individuals who had jurisdiction over cases involving citizens and foreigners. Jus naturale was a concept the jurists developed to explain why all people seemed to obey some laws. Their answer was that a "natural law" instilled in all beings a common sense. ius scriptum and ius non-scriptum – meaning written and unwritten law, respectively. In practice, the two differed by the means of their creation and not necessarily whether or not they were written down. The ius scriptum was the body of statute laws made by the legislature. The laws were known as leges (lit. "laws") and plebiscita (lit. "plebiscites," originating in the Plebeian Council). Roman lawyers would also include in the ius scriptum the edicts of magistrates (magistratuum edicta), the advice of the Senate (Senatus consulta), the responses and thoughts of jurists (responsa prudentium), and the proclamations and beliefs of the emperor (principum placita). Ius non-scriptum was the body of common laws that arose from customary practice and had become binding over time. ius commune and ius singulare – Ius singulare (singular law) is special law for certain groups of people, things, or legal relations (because of which it is an exception from the general rules of the legal system), unlike general, ordinary, law (ius commune). An example of this is the law about wills written by people in the military during a campaign, which are exempt of the solemnities generally required for citizens when writing wills in normal circumstances. ius publicum and ius privatum – ius publicum means public law and ius privatum means private law, where public law is to protect the interests of the Roman state while private law should protect individuals. In the Roman law ius privatum included personal, property, civil and criminal law; judicial proceeding was private process (iudicium privatum); and crimes were private (except the most severe ones that were prosecuted by the state). Public law will only include some areas of private law close to the end of the Roman state. Ius publicum was also used to describe obligatory legal regulations (today called ius