How does being a nation of laws both protect and limit freedom?

A nation that rules by written laws that was created by an elected government b y the people can protect its citizens from arbitrary prosecution and trials or procedures devised by a prejudicial Judiciary. This is because the laws provide for the equal treatment of its citizens.

According to the written laws and the fair application of them gives citizens the confidence that they live in a just society.

Just as the laws and description above applies to all citizens, certain limits of any society must be part of the legal system to avoid excesses in behavior. As an example of this, a society may have laws pertaining to the acquisition and use of fire arms. No matter what the law curtails, and whatever some citizens may wish, these type of laws restrict freedom for the benefit of all.