Optimal Population again

A friend argues, we must have large as present society, or are doomed to 19th century technology.  I reply:

An interesting research project in itself.  I'm following the original Limits to Growth estimate range, 500M - 1B, I believe.

Population size ought to influence the rate of technological change, not necessarily the level of technology itself, which does change over historical time with population and other influences.  Anyway, I believe the rate of substantive technological change was at it's greatest precisely in the 19th century, during which time transcontinental travel times dropped 100 fold, and so on.  Telephony was broadly available in 1900 and radio flourashing by 1920--one hundred years ago.  Since then, radio has become an even bigger part of telephony.

Recently, technological change hasn't been about moving people around more efficiently, that continues along the old most profitable means, pretty well established by 1950, it's been around moving people's heads around inside, by and large in order to sell them more stuff to do just that.  That's post-Industrial technological change, about profit and little else.  And barely keeping up with the demands of more people--falling behind in many areas--by simply sand bagging long unsustainable processes.  This can't continue for long.

The 19th century changes were wrong too, I suppose you could argue.  But at least they achieved great feats in the material world, rather than in our heads and in financial engineering and falsely extrapolated future opportunities.

Certainly the optimal human population ought to permit a wide variety of aboriginal ecological domains.  Human controlled areas ought to amount to far less than half, and not just where it's uninhabitable.

This is true both for our own existence, which relies on many uncounted processes, but for a fundamental ethics.  We humans ought to be the stewards and admirers of our biological envelope, not the willful destroyers of it.

And part of the essence of that biological envelope is its widely diverse species, which our dominance and unintended effects tend to make widely extinct.

Therefore we must not only think of what might be possible with well conducted and utilized technological progress, but on the real progress likely, which is nil without fundamental social reform to a society that might well work ok with decreasing population, rather than relying on ever increasing population to maintain order.

Even under continually improving decisionmaking, current population levels are a drag, including on meaningful technological change.  Under the best imaginable decisionmaking, current population levels might barely work.  Under the most likely decisionmaking procecsses, the results of anything less than the mild population reductions I am proposing will be catastrophic to the earthly life including humanity.

Most important will still be moving toward a more rational and ethical governance.

Further, population growth under any fully voluntary regime will be axiomatically dominated by pro-birthism religions and their like.  They will be populating at 300% of current leveles, and the rest of people in the post Me Too age of post modern sexuality, more like 25%.  Selection will inevitably favor religious kooks, and no plan of "women's education" will coopt these breeders as they provide their own educational milleau and will not be dissauded from educating women to view things their way.  The only thing that does ultimately happen is that some fall away, but enough remain to keep the system going.