Yeah it makes sense. The desert island is just a useful metaphor for me. If another person showed up on my island, for example, would I have a right to that person's things? If I had a right to that person's things, I also had a right to them when alone on my island.
For me, rights are an intrinsic part of the human. You can't seperate the human from his rights. To do so makes the person less than human. A person's rights cannot be alienated from the person- ie he cannot exist in a different sphere than his rights. So your rights are something you would have with you whether you are alone or in the middle of a mega-city.
If I am alone it doesn't matter much and like you said it only comes into play as a concept to be acknowledged and respected when other people enter the mix. But the desert island is useful in seeing what is intrinsic to the human and what is not.
Let's say my visitor on my desert island is a doctor. Do I have a right to his skills? Well no. I have a right to go up and ask him to help me but whether he does or not is up to him. So if the doctor is there or not I have no intrinsic right to medical care.
It's like I said, it is merely a useful tool for me. It has its flaws. It is best used only as a general rule of thumb, a sort of jumping off point to deeper considerations.
America is unique in history in that it was the first nation to be founded on the principle that individuals have rights, and that the only legitimate function of government was to protect those rights.
Too darn bad we've strayed so far from those ideals. In modern America, most people think you do have a right to the skills of doctors. I think that FDR was the first one to overtly change the definition of "rights" with his "Four Freedoms" state of the union message.
In the future days which we seek to make secure, we look forward to a world founded upon four essential human freedoms.The first is freedom of speech and expression --everywhere in the world.
The second is freedom of every person to worship God in his own way -- everywhere in the world.
The third is freedom from want, which, translated into world terms, means economic understandings which will secure to every nation a healthy peacetime life for its inhabitants --everywhere in the world.
The fourth is freedom from fear, which, translated into world terms, means a world-wide reduction of armaments to such a point and in such a thorough fashion that no nation will be in a position to commit an act of physical aggression against any neighbor --anywhere in the wold. That is no vision of a distant millennium. It is a definite basis for a kind of world attainable in our own time and generation. That kind of world is the very antithesis of the so-called "new order" of tyranny which the dictators seek to create with the crash of a bomb.
FDR slyly mixed in the false "right" to the labor of others in with valid rights like freedom of speech and worship. He also snuck in the false concept that governments have rights, and people do not.