In fact, laws are built the old-fashioned way, on a foundation of 'interest'.
That's why it's important to keep politicians and lawyers on a short leash; they'll ALWAYS run with whatever power EXISTS.
No idealists they. ;^)
What if it's in my interest and within my capacity to break laws without punishment? Why would I abide by them unless keeping my word or the act of the lawbreaking was in some way wrong?