“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.”

Those words, published for all the world to see some 239 years ago this weekend, have proved to be among the most powerful ever written. Their author, Thomas Jefferson, took a somewhat vague sentiment that had been bubbling up in the American colonies and crystallized it into a bold, earth-shaking assertion.

And the rumbling hasn’t stopped, as those words continue to challenge us today. They were, for example, the direct cause, inspiration and justification for the Supreme Court ruling last month that gay Americans have the same right as everybody else to marry whom they choose.

Gay or straight, we are created equal. We have, all of us, certain unalienable rights. And among these are life, liberty and the pursuit of happiness. Surely the right to pursue happiness includes the right to marry the person of your choice.

Opponents of the Obergefell v. Hodges ruling are admittedly correct when they argue that Jefferson would probably be horrified and astonished to learn that his words were being applied to same-sex marriage. That wasn’t what he had in mind. They are also correct that in the past two centuries, we have expanded the meaning of terms such as equality and liberty significantly beyond what Jefferson had imagined.

But while some see that as a problem, I see it as validation. We are making his words our words. We are taking sentiments and thoughts expressed on a dusty piece of parchment in another era and we are keeping them alive, vibrant and relevant to our own time.

If you believe that liberty and equality are static concepts, it’s worth pointing out that when Jefferson expressed those words in ink, when Georgia’s own Button Gwinnett became the first person to sign it, it was only men who were considered theoretically equal. Only white men. And in many colonies at the time, it was only white men who owned property.

Jefferson supported a property requirement to vote, as did John Adams, his co-author of the Declaration. If you give the right to vote to those without property — the renter, the workman, the servant, the city dweller — “every man who has not a farthing will demand an equal voice with any other, in all acts of state,” Adams warned. “It tends to confound and destroy all distinctions, and prostrate all ranks to one common level.”

But Benjamin Franklin, who often had what we would consider a more modern sensibility, thought that property requirement ridiculous:

“Today a man owns a jackass worth 50 dollars and he is entitled to vote; but before the next election the jackass dies. The man in the mean time has become more experienced, his knowledge of the principles of government, and his acquaintance with mankind, are more extensive, and he is therefore better qualified to make a proper selection of rulers — but the jackass is dead and the man cannot vote. Now gentlemen, pray inform me, in whom is the right of suffrage? In the man or in the jackass?”

The answer, as we came to understand, was in the man, and not just in the man but in the person.