Is law purely the translation of the ethical idea of justice, or is it something more?

The above ‘title’ is based on a comment in the article – The Medieval Idea of Law (Walter Ullman). The article discusses the role the Glossators, who rediscovered ancient Roman legal texts, played in the advancement of Roman law; and the Post Glossators who expanded the early work of their predecessors and developed Roman law into something more than just ideas, more than just a virtue. The Glossators did not attempt to harness any new concepts to the ancient texts, they simply commented upon them using their singular belief that law was only based on Justinian teachings. The Post Glossators took this and built upon it, introducing a philosophical undercurrent. They formed a highly regarded European school of legal studies, creating universities such as those in Bologna, Peruvia, Padua and Siena; and devoted much of their energy to determining how law could be applied in practice rather than just principle.

Law is a system for governing society, a way to maintain, support and protect public order, and as such it cannot be based just upon one tenet as the Glossators suggested. In my view, and in common with the notions put forward by the Post Glossators, law is not only based on an ethereal notion of justice, but has as its cornerstones morality, philosophy, religion, history, science, sociology and yes, ethics. Therefore the many and various ideas introduced and evolved by the Post Glossators helped to develop law from a narrow concept into a multi faceted principle.

But were they correct? Were their endeavours misplaced, and is too much made of law today. Should law be an insular notion, untroubled by consideration of philosophical and moral direction?