French civil law and German civil law were developed sufficiently different.
Each subdivision is complete for itself, and there is no need of having interest
or learning the other one. There is a list of arguments for this statement below.
Both branches of civil law took its origin from the Roman law. During the
Revolution, France took the Roman law and promulgated it without major changes.
On the other hand, German civil law is also based on the Roman law, but it
considerably changed its content. That is why the second term regarding the
civil law is Romano-German law system. The term adds the word German, because of
addition of German law to the system.
For French civil law the law would be only acts of parliament. For German civil
law customs also had great power, when it comes to choose between law and custom.
During the Revolution and codification period emphasis pushed on nationalism,
escaping from jus commune which meant common to all. Nevertheless, French and
German civil law basically arose from the Roman law, each subdivision tried to
give a different form to the same law, so it could easily be recognized as
French law or German law.
Another point is that, thoughts regarding to law was totally different in two
civil law subdivisions. German law was essentially based on Sevigne’s school of
thought and this school of thought was rejected in France.
Therefore, two subdivisions are complete for themselves. Each subdivision does
not feel in need to the other subdivision and even it could feel, most of laws
would not be compatible to each other. The only thing which is keeping the two
subdivisions under whole civil law system is their source-the Roman law.