Two hundred and thirty-five years ago today, these words were approved by the Continental Congress of the United States of America:

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed.

When I first read this as a child, I wondered about that word "unalienable". At the time, it was explained as simply meaning a "natural" right, one that, as this Wikipedia page says, is "not contingent upon the laws, customs, or beliefs of any particular culture or government." That seemed straightforward enough, but then why didn't the Declaration just say "natural" or "innate" or something like that?

Then there was another wrinkle; some versions of the Declaration that I saw in school used the word "inalienable" instead of "unalienable". As a matter of fact, this picture shows the inscription of the opening of the Declaration in the Jefferson Memorial, which clearly uses the word "inalienable", not "unalienable", even though the official transcript in the US government archives clearly says "unalienable".

Is there a difference? The same definition was given to me for both words in school, but this webpage quotes several law dictionaries that assign different meanings to the two words. According to these definitions, an "inalienable" right is one that cannot be given up or transferred except with the consent of the holder of the right; an "unalienable" right is one that cannot be given up or transferred period, even if the holder of the right wants to.

This is a significant difference. Either way, of course, there is something more to our rights than just being "natural", as opposed to being granted by law or custom; they can't be taken away from us without our consent. But the original Declaration, by using the word "unalienable", meant, I believe, to say that we can't give up these rights even if we want to. In other words, they are not just rights that we should expect others to respect; they are rights that we owe to ourselves, because they are part of our nature as human beings, and thinking that we can choose to give them up, or trade part of them for something else (such as security), is like thinking that we can choose to have the laws of gravity not apply to us.