p. 20:  The emergence of the modern nation-state destroyed the legal unity provided by the common acceptance of the Roman-canonic ius communein feudal Europe.  The ius commune, associated in many minds with the concept of the Holy Roman Empire, was a law that transcended the diversities of local tribes, communities, and nations.

Law:  Sources of Law pp. 19-25

Civil:

Common:
 

Codification  pp. 26-33; 48-55

Role of codification in civil law;  in common law
 

Procedure  pp. 34-38; 80-89;  111-132

Common law:

Civil law:
 

Role of the Jurists  pp. 61-67; 101-110

Common law:

Civil law: