I think that a pure communist society (which has very little to do with "Communism" as the countries that have designated themselves as communist up to now have practiced it) would work perfectly, if all the members of the society conducted their lives thinking only of the good of the society as a whole, without any concern for their personal desires. Of course, that isn't going to happen.

I think that a pure capitalist, libertarian, society would work perfectly if all the members of the society conducted their lives thinking only of their own personal self-interest - but their long-term self interest. Of course, that isn't going to happen either.

I think that the two societies that would result in the above two ideal cases would be hard to tell apart.

In the meantime, we need to strike a happy medium (flash of a guy in a robe looking into a crystal ball and giggling, while someone whacks him with a stick).

Peter.