If you want to grapple with some really tough cases, David Friedman presents a few in The Machinery Of Freedom. One of my favorites runs like this:
A madman is rampaging through a crowd, taking lives right and left. No one in the crowd is armed, whereas the madman is, heavily. However, there's a loaded rifle in plain sight -- on the front porch of an old curmudgeon whose made it known that he is unwilling for anyone to come onto his property for any reason.
You're a crack shot. Given that rifle, you could drop the madman where he stands. But according to strict property rights theory, you'd be committing a trespass to touch the rifle. What do you do?
Any sane man would blow a razzberry at the property-rights issue and do what obviously needs to be done, secure in the knowledge that no jury in the world would convict him for his trespass. Property-rights purists, for whom nothing justifies an invasion of others' property, would be paralyzed.
As Friedman points out in his study of this case, there are no "trick" answers, for the conditions can always be straitened to foreclose any choices but violating the curmudgeon's property rights or allowing the loss of innocent lives.
Other important boundary-problem issues exist in dealing with children, madmen, abortion, border control, foreign policy and military affairs.
Freedom, Wealth, and Peace,
Francis W. Porretto
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