What is the name of the problem introduced by Plato as an illustration of the relationship between religion and ethics?

Euthyphro dilemma.

Explanation:

Euthyphro dilemma was introduced in Plato's dialogue Euthyphro. In this dialogue Socrates asks Euthyphro about the piety - a virtue that includes spiritual devotion and humility. Socrates asks if piety 'is loved by gods because it is piety, or it is piety because it is loved by gods?'.

Applying this dilemma to the modern legal matters, the professor Myres S. McDougal from the Yale Law School asked if the property rights are protected because they are property rights, or they are rights because we protect them. Fundamentally this question asks if property rights are natural or given.

This dilemma can be addressed to various matters to identify if this matter has true value in itself, or only because something says so.