For example presumed innocent until proven guilty is a principle of common law. Does it apply in every country which has common law?
4This seems like a tautology. If some basic principle of common law is only observed in some common law jurisdictions, then either the other ones aren’t common law jurisdictions or it isn’t a basic principle of common law.– SneftelJan 11 at 8:30
2Also, the thing that makes common law distinct is not presumption of innocence - that’s pretty common across most legal systems; it’s binding precedent.– Dale M ♦Jan 11 at 11:27
Common law does not apply in countries that follow the legal school of Code Civil, aka civil law legal system, such as Germany or France. Some basic principles are common between them and common law: While there's generally no right to a jury, the innocence part actually stems in both cases from ROMAN law: in dubio pro reo - in the case of doubt, (you have to decide) for the accused. The similar Ei incumbit probatio qui dicit, non qui negat - Proof lies on him who asserts, not on him who denies - is the source: It was butchered into "innocent until proven guilty", but the sentiment is the same.
Other countries that have no relation to common law are based on Sharia and Fiqh. There is absolutely no relation to Roman law either. However, there is a presumption of innocence, or as one of the largest Scholars of Islamic law Caliph Ali ibn Abi Talib said in the mid-600s: "Avert the prescribed punishment by rejecting doubtful evidence." However, what is considered doubtful is quite different.
On the other hand, presumption of guilt was the foundational principle in other legal systems!
The principle of "presumed innocent until proven guilty" is a fundamental principle of common law and is widely recognized in countries that have a common law legal system, such as the United Kingdom, the United States, and Canada. However, the application and interpretation of this principle may vary between different jurisdictions. It is not universal across all countries that have common law, some may have variation or different legal system which result in different principle.