I hear a lot of Conservatives ridiculing "Progressives" for seeming to be against progress. After all, everything that they do seems to go against any real progress as you and I define the term. In fact, their entire philosophy is rooted in the long-dead mind of a Leftist misfit who lived over 100 years ago. How's that for progress?
But to understand how a Leftist defines progress you only need to remember one thing: Socialism was an imperfect but necessary step in progressing to the "perfection" of real Communism.
In the old Soviet Union, where the population was constantly inundated with short, propagandistic slogans (now, who has the "bumper sticker" ideology?), one of the most prevalent consisted of the word 'Progress!'
In fact, during the Soyuz space station days, the space vehicle used to resupply the station was even named Progress.
Their entire system was designed to create the conditions necessary to progress towards International Socialism first and, eventually, to real Communism where every person was exactly the equal of (i.e. the same as) the next. Little robots that the State could use (and destroy) however it saw fit.
And so, when you hear anyone calling themselves a "progressive", trying to see in their ideology what any sane person would call progress is utterly futile. It's apples and oranges. We're not speaking of the same thing.
We're speaking of the betterment of mankind in terms of liberty, freedom, science, etc.
They're speaking in terms of the progression of mankind to be servants of the State.