Step 1: Understanding the Concept:
The Hart-Fuller debate is one of the most famous jurisprudential debates of the 20th century. It took place in the pages of the Harvard Law Review in 1958 and centered on the relationship between law and morality, particularly in the context of wicked or unjust laws (like those of Nazi Germany).
Step 2: Detailed Explanation:
- H.L.A. Hart: Represented the school of Legal Positivism. Hart argued for a strict separation of law and morality (the "separation thesis"). He believed that a law could be legally valid even if it was morally abhorrent. For Hart, the validity of a law depends on its source and pedigree (the "rule of recognition"), not on its moral content.
- Lon L. Fuller: Represented a modern version of Natural Law theory. Fuller argued that law has an "inner morality" or a set of procedural principles that a system must meet to be considered a legal system at all. He called these principles the "eight principles of legality" (e.g., laws must be public, clear, non-contradictory). For Fuller, a system that grossly violates these principles (like the Nazi regime) does not just create bad law, but something that cannot be properly called "law" at all.
Therefore, the debate is a classic clash between the Natural Law perspective (Fuller) and the Legal Positivism perspective (Hart).