What is the difference between a "right" and a "privilege."
For me, a right is something that exists by virtum,o9-0e of being a human being. I have a right to believe as I will, no matter how loony my particular beliefs might be. I have a right to call someone a loony, even if they are as smart as Einstein and as wise as Solomon.
A privilege is something that I don't have unless someone else gives it to me. My neighbor gives it to me, perhaps: My neighbor invites me into his house for dinner. That's a privilege, my neighbor's to grant and take away as he wills. Or maybe it's granted by the govenment. Most people would consider a license to practice law or medicine or hair styling is a "privilege" granted by the state.
Your "title" in your real estate is a privilege: almost all "private property" titles are there because of a grant from King or state. And yes, that title is a revocable privilege: the state can take it back. (thanks to the law of eminent domain, only for a "public purpose" and only with compensation.)
On the other hand, it's not clear, at least to me, whether those "public purpose" and "only with compensation" requirements constitute "right" or "privilege".
Privileges can be taken away. Rights cannot.
All that people can do with respect to another's right is stop or limit its exercise. But if the right exists, stopping or limiting its exercise will be an immoral act
unless a separate and superseding right is found
and unless it is demonstrated that the method protects that separate and superseding right.
Power can infringe a right; it cannot by itself make the infringement moral.
So Shawn's point about "right or privilege" is the real issue here. (His conclusion is wrong, IMO, but he's definitely got the question right.)
Why should air travel be thought a right, rather than a privilege?
My answer is in too steps. First, because "being able to move and travel about" is a right. And second, because "other travel options" are not equivalent.
Why is being able to move and travel about so important? It allows escape from bad situations and allows movement toward better ones. It allows us to associate with who we want to associate with. It allows us to act upon our preferences and our values. You can't pursue "life, liberty, and the pursuit of happiness" unless you are able to move about.
Why are other travel options not equivalent? To be blunt, they're more expensive. Not necessarily in the sense of money, but in the sense of "what must be sacrificed" to do so. I don't need a plane to go to Portugal or to Denver. I can get to either place physically in other ways. But only if I make a lot bigger sacrifices -- Portugal's going to take more time and money to get there by car/ship/train; Denver's going to take more time and dealing with other drivers and getting lost on the highway and dealing with car breakdowns, etc.
If I had no right to travel and move about, none of these "extra costs" would be relevant. But if I do have that general right to travel, they are. Because now those differential costs are being imposed by a restriction on a right. And so the burden has shifted: those wishing to limit my right to travel must explain why they are justified in doing so.
If they don't, then they may still have the power to restrict and shape my choices. But they have no moral authority for doing so.
They have no more moral authority than those who used their power to treat people as serfs. If moving and travelling about is a privilege, then only allowing the serf off the manorial lands under very limited conditions, or not allowing them off at all, then the lord of the manor had moral authority for the practice of serfdom. But if moving and travelling about is a basic right of human beings, then serfdom was morally without authority.
And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
Romans 12:2 (NKJV)