in addition to this, due to a removal of monetary constraint and thus desire, most if not all criminal activity would be removed simply because there would be no motivating factor behind the committing of most crimes. it is argued (and i cannot say i entirely agree) that humans are NOT intrinsically selfish.
we act not due to human nature, but due to human nurture. our environment (of capitalistic ambition) dictates our behaviour, not our instincts.
I have to disagree with this to an extent. As natives to the planet earth and therefore a product of 3.5 billion years of evolution, there are certain basic drives that humans can't ignore. One of the most basic is to pass on our genes. A corollary therefore, is our need to win mates. By extension of this, we seek to raise ourselves above the 'common masses' (other mates) by some form so we stick out to other prospective mates. Another extension of passing on genes is our need to safeguard our offspring and give them the best chance at passing on their own genes (and therefore, our genes). What I'm getting at, is humans ARE intrinsically selfish, it's all a product of natural selection. So are squirrels, creeping vines, nematodes, and bacteria. Organisms that seek to better the lives of other organisms over their own are promptly bred out.
The only thing humans have done is replace the biggest hoarde of nuts that the squirrel greedily tries to acquire with the biggest pile of money, the best TV, or the most fashionable clothes (i.e. A lion's mane). But it all boils down to the same drive: Win the best mate by being the most attractive option, pass on the genes, and ensure your offspring's survival and fitness.
This is where capitalism is able to harness the basic human desire to better oneself and one's standard of living - greed. To deny some level of greed is to deny part of what makes us living, evolving, organisms. This is also where the 'small-government' pure capitalists open themselves up to prove the idiocy of unregulated capitalism. You can't expect to base an entire economic system around the human desire to better oneself and then not expect it to get out of hand (current economic problem).
This is also where communism falls flat on its face. Communism is a great idea on paper, but who the hell wants to work 2 hours more a day in the field so 'the people' can be better off? The people doing the work see no tangible benefit to giving 110% over the easy life of giving 80%. The data's pretty clear in this regard, most recently regarding rural rice farmers in China. Production triples when you let the farmers reap the benefits of additional output. Abolishing money just means that people are going to steal something else to better themselves (i.e. make them more fit to pass their genes on). Someone else always has a better TV, car, more food... whatever.
Without inequity, we could experience some sort of analogy to evolutionary stagnation.
HOWEVER, in saying that, in order to have a functioning, thriving, and harmonious society, everyone has to have the ability to have their basic needs met (everyone has to have a realistic shot of eating, staying dry, fucking, and raising a child). This is where some sort of happy medium between pure communism and pure capitalism is required - socialism.