Custom – Its Nature and Position in Roman Law

Abstract

The terms used to designate sources of law have roots in Roman legal terminology: law and custom (lex and consuetudo). The term mos (mores maiorum) originally referred to the legally binding usages of ancestors, but it was also used to mean socially accepted moral or social order. It is difficult to determine what the later terms lex and consuetudo referred to exactly. It would be bold to transfer our modern categories and consider laws to be general rules issued by a sovereign power and customs to be naturally arising and accepted usages. Although roman lawyers did not deal with custom from a theoretical point of view, the problem of the connection between laws and customs arose in legal practice. The position of custom was gradually confronted with changes in law making, especially with the establishment of jurisprudence as a key element in the system of sources of law and later also with the dominant position of imperial law making. Nevertheless, the importance of custom never definitively disappeared, but its power compared with lex, or imperial constitutions, was suppressed as a result of the dominant position of imperial legislative authority.