Capitalism wants us to believe that it’s the only stable solution, because it comes close to the natural order, and that in nature there is only selfish behaviour, eat or get eaten, homo homini lupus and so on. The truth is, this supposed natural state is completely made up and animals and human beings naturally behave much more selflessly than what is expected from us under capitalism.
Thing is, even the phrase homo homini lupus predates capitalism significantly, and the sentiment dates back to before even the phrase. ‘Naturally behave’ is a very questionable phrase.
We have the ability to be better and build better societies than we currently have under capitalism. I just don’t think an appeal to a state of nature is useful or accurate.
I think there is definitely a line from early modern natural state theory to today’s justification of capitalism, although the argument has somehow reversed itself.
Actual natural behaviour is not even important, since we abandoned that some time ago, and it probably isn’t desirable to go back. Its just easier to sell an ideology when you disguise it as natural order.
I’d say it’s more of an easy to make justification than a real argument. History is incredibly long and full of varied situations in which creatures have survived in many different ways, so it can be mined for examples to support almost anything and claim it to be “natural”.