What a sensibly reasoned article.
Simon, you have raised many matters which we in our informationally overloaded society tends to ignore.
One example is your statement that 'we are far more inheritors than constructors.' How true.

We often fail to see that impermanence is a constant; nothing stays the same. When confonted by this fact, we sometimes resort to compensating for our confusing evolvement by blaming the outcome of that behavioural development which is outside our own creation or control.

You are stating that we need to build upon the positive processes and behavioural practices initiated by others. This involves the need for a good ability and moral foundation in order the judge the accepatbility of the myriad of changes proposed over very long periods of time.

How assuring to be reminded that we are not what we once were - we've grown!

Nice article

it has often struck me as ironic that self-described "progressives" are often the last to acknowledge evidence of actual progress.

Excellent.

An incoherent rant that seems to want to white-wash past, present and future, withal their enormities, as some sort of blundering progress we should celebrate.
I think I understand the ideology behind this bravado, which omits to spell out its poisonous logic...

Progress is not evolutionary, and can't be ascribed post hoc to historical accident or random opportunism.
Progressivism is an idealistic agenda which, hitherto, has been trusted to economic and technological innovation.
That is, to entrust the idea of progress to the free market, which has been anything but progressive in any qualitative, humanist sense.

Genuine progress into the future must take the form of deliberative action, idealistically inspired, rather than faith placed in an indifferent mechanism.

Mundy seems to want to celebrate what we are (and what are we that we should celebrate?) regardless of how we got here; to cast aside idealism and embrace instinct. His thinking is as raw as his prose.

Simon, you identify as a “progressive”. You say that “we have come a long way AND we have farther to go”.

But what specifically are we supposed to be progressing toward?

Do you have some absolutely certain insight as to what the goal is that we are to be aiming for?

How did you gain that insight?

What do you say to anyone who may disagree with you as to what the goal is that we should be progressing toward?

It is surely necessary for you to clearly answer such questions if your article is to have any value.