I found it on the Arts and Letters website that you turned me onto.
Pinker wrote it for the New Republic and this is the link.
He says what you said, only longer. But he had a word count to reach.
In the end I think he means that, like values, everyone has their own definition of what's dignified and what's not-- so it's not measurable. They're words that carry a lot of emotional baggage, however, so they can sway opinion.
Am I using too many commas?