Ever since the 17th century, the rule of law has been regarded as one of the fundamental values of a free society. It means you cannot be forced to do something unless there is a law requiring you to do it.
It also means people in power can coerce you only if there is a rule justifying it. This is the opposite of the “rule of persons”, in which the rulers have arbitrary power: they have the authority to force you to do things simply because they think those things should be done.
