Thanks for the compliment, Poirot, though the credit goes to Peter Hume; he makes a wonderful foil!
Peter Hume:
<if capitalism involves indefinite [sic] growth on a finite base, and if indefinite [sic] growth on a finite base is unsustainable, then we can logically conclude that capitalism is unsustainable, which is obviously the principle of reason you were using.>

Dear Peter Hume,
A "vague" proposition but I take your meaning. Putting it in formal terms yes, one premise is that capitalism's inner logic is untenable.

I have to observe before I go on, that reading through the morning posts (who needs newspapers), it seems to me a part of your strategy (whether intentional or subliminal) must be to obfuscate with verbiage; otherwise, I'm bound to observe that your style, reminiscent of petty legalese, is more productive of ink than import.
However.
Your point 2: <The argument from economic calculation shows by logical reasoning that any alternative system must be more unsustainable than the private ownership of the means of production – capitalism.>
This and what follows seems, first of all, to rationalise that economy must be systemic; ergo, if sustainability is the goal to be wished for then the "mechanism" must attain the utmost in efficiency. Indeed, if "sustainability" is the goal, then any such abstract principle of economic control must needs be tantamount to a perpetual motion machine! I do not pedantically allude here to the problem of entropy, which of course must come into any calculation ultimately, but to the more immediate problem of human gremlins that would surely infiltrate any systemic approach--witness your own instance of torches shone on solar panels. In other words I would tentatively argue that human economy must be flexible, self-reflective and adaptable, hence my insistence on guiding ethics.

In any event, if you are proposing capitalism as the most efficient systemic means of regulation, a system not merely devoid of ethics but predicated on their very antithesis, this is also a demonstrable fallacy:

<...to be more sustainable, a system must use less resources to achieve a given result. To do this, it must have some way of knowing whether a given use of resources is more or less wasteful. Should the house be built out of pine, or hardwood, or teak, or steel, or zircon, or straw, or silver? What tools or machines should substitute for what labour?

In a system based on private ownership of the means of production, these questions are answered by comparing money prices for the different factors of production. But that is only possible because money prices provide a lowest common denominator in which all the different resources on the market can be valued.>

cont.

cont..

This is patent nonsense, since you don't account for the ingenuity and lengths humans will go to to exploit a breach (such as dairy farmers watering down milk). And even if you could render the system impervious to opportunism, you don't account for the insatiable bourgeois taste for luxury. What is the use of attaining wealth in a competitive system, after all, if you don't flaunt it? Thus, the utterly unsustainable phenomena, in the West, of McMansions and SUV's etc., are directly attributable to the "efficiencies" you are seeking to defend! The obscene obverse is that these "efficiencies" are also the means of impoverishing the working classes whose exploitation is fundamental to maintaining this vast disparity between rich and poor. What keeps this bipolar system going is the bourgeois phenomenon; the middle aspirational classes who maintain the status quo via their perpetual enchantment with the gilded carrot. Yet it is surely CDF that the whole world (even if its resources were infinite) cannot join the ranks of the bourgeoisie. The phenomenon has spread, more or less, across Australia (thanks largely to natural resources but it cannot last), which is why we have a labour shortage, but how can capitalism bring this prosperity to the whole globe? It cannot.
We would be hard pressed to find a system less efficient, sustainable or morally demeaning than capitalism!
But that's all I (don't)have time for now.

Severin re - Thanks for the excellent definition of FASCISM.

Well what is in a name,

I said previously "collectivism by any name"

"Fascism" is "collectivism" by a different name

Personally, I could never identify the real difference between communism and fascism (apart from a small difference in the ownership of some assets who were subordinate yet, walking in lock-step with a too powerful government bureaucracy)

and as Lenin said

the goal of socialism is communism

therefore if you are suggesting

the eventual progression and consequences of socialism is fascism

I doubt I could ever find any reason to disagree with you

Nice of you to acknowledge the damning 'end-game' of progressive labor party political philosophy

I think I will remain a libertarian capitalist, since I do not wish to control every dollar you might lay claim to and moment of your day

*What is the use of attaining wealth in a competitive system, after all, if you don't flaunt it? Thus, the utterly unsustainable phenomena, in the West, of McMansions and SUV's etc*

Not so Squeers. You will find plenty of wealthy people who don't
flaunt it, you'd often never know that they were wealthy.

Those who flaunt it, commonly do so with borrowed money,
low self esteem or other drivers perhaps?

Wealth is often a byproduct of people doing what they love
doing and are passionate about. Some people really are passionate
about running their businesses. Wealth created is simply the
way of keeping score, if they are doing it right or not.

The generation of wealth gives you the option of doing the things
you want to do, rather then the things you have to do. That
includes the option of being innovative, which is how we make
most of our progress.

SUVs can make sense from a pure safety point of view. I was
once backended by a young lady driving a lightweight Asian car.
My towball had a couple of scratches, her car had 3000$ worth
of damage.

Squeers - We would be hard pressed to find a system less efficient, sustainable or morally demeaning than capitalism!

Oh do not want to acknowledge recent history?

See the list in my post of Monday, 12 July 2010 8:03:35 AM

I see nothing more demeaning than a government which:

is appointed by revolutionaries or electorial fraud

demands control of all resources

kills any citizen who dares express objection to governmental abuses of power.

remains incapable of feeding its population.

chooses to murder those who flee its authority

All the above claims can be levied at all the "collectivist" / anti-capitalist governments I listed (except Mugabe, who was actually elected in supervised elections to abuse his electorate but was reappointed by electorial fraud).