Laid side-by-side, a stick and a rope of the same length share a similar appearance.
Likewise, rules and principles look alike even though they have virtually nothing in common.
Rules are like sticks.
You can prod people with them.
You can threaten people with them.
You can beat people with them.
But you cannot lead people with them.
When a rule doesn't fit the circumstance, your only choice is to break it.
Principles are like ropes, able to conform to the shape of any problem. They are less brittle than rules, and stronger. Principles whisper valuable advice and people are happily led by them.
A rule requires obedience.
A principle requires contemplation.
Rules are demanded by people
who have not the wit to understand and apply
the appropriate, all-encompassing principle.