Capitalism promotes (unrepentant, unrelenting) greed, then it points at the world and goes "look how greedy people are! it's a rule of nature!".
It's all a ruse, a self fulfilling prophecy. The truth is, simply, people will do as the system rewards. In a society where brute force is glorified, people will be brutes and the world will be cruel. In a society where scholars and scientists and artists are valued and rewarded, there will be more scientific progress and cultural output. The humans themselves are the same as they have been for 100,000 years, its just the culture that changed between cavemen, renaissance Italy, Mongol hordes, and modern day growth capitalism.
In a world where greed and individual selfishness is the one metric that is rewarded, guess how most people will behave. That in a system such as ours most people are still good and altruistic and empathetic speaks volumes to how wrong that thesis is.
The question is, why do people do as the system rewards? Why do they strenuously seek out rewards to be gained in any system, to such an extent that they'll change their apparent nature to do it? That sounds like greed to me. The fact that capitalism sets up the reward structure so that if you're really greedy one of the best ways to succeed is make something people really want, or something that increases efficiency, it's a really useful coincidence.
Also, you say humans have been the same for a 100,000 years, which seems to indicate that there is a human nature, and that society hasn't really changed them. Isn't that the opposite of your earlier point? It certainly supports the capitalist point, if you actually examine how people acted in history. Especially if you look at what happens to systems of government and economics that rely on people being altruistic and not greedy (the Church, communism, monarchy to an extent).
Also, I'd like to point out that in any society, but especially in a humanist, free society where being altruistic is a choice and not something forced upon you, there is always a reward for being altruistic, whether it's internal conscience assuaging, or extrnal favor-gaining. Furthermore, it is completely possible to be greedy in the persuits of gaining money, and then altruistic later: the whole point of getting money is not to have it, but to use it they way you want to use it. That can include charity.
>In a world where greed and individual selfishness is the one metric that is rewarded, guess how most people will behave. That in a system such as ours most people are still good and altruistic and empathetic speaks volumes to how wrong that thesis is.
If the current system is based on rewarding greed, and systems like that make "most people" behave greedily, then why are "most people" behaving altruistically? Either our current system is not one that rewards greed, or you have a contradiction. This contradiction reveals a lot about how you view people and the system.
It's not a contradiction. Our system rewards, promotes, glorifies unremitting greed, yet the average person is still not a profit-maximising fiend, with at least some considerations of morality, altruism, etc. This only contradicts the above thesis that humans are inherently greedy and selfish and capitalism merely mirrors (rather than promotes) this.
It's all a ruse, a self fulfilling prophecy. The truth is, simply, people will do as the system rewards. In a society where brute force is glorified, people will be brutes and the world will be cruel. In a society where scholars and scientists and artists are valued and rewarded, there will be more scientific progress and cultural output. The humans themselves are the same as they have been for 100,000 years, its just the culture that changed between cavemen, renaissance Italy, Mongol hordes, and modern day growth capitalism.
In a world where greed and individual selfishness is the one metric that is rewarded, guess how most people will behave. That in a system such as ours most people are still good and altruistic and empathetic speaks volumes to how wrong that thesis is.