ec2-3-14-153-176.us-east-2.compute.amazonaws.com | ToothyWiki | RecentChanges | Login | Webcomic In any society which is not a PostScarcity? society, there will be jobs to do. In order to get people to do the jobs you need to encourage them to do so. In a capitalist society, the motivator to do this is cash. In other societies, there are other things such as your position in society, appeal to goodwill (Communism? says 'from each according to their ability, to each according to their need'), force, and so on. Of these methods, cash is arguably the most effective and the best, for the following reasons:
Cash is knowledgeless. When using cash, you do not need to know about the other person. This allows the society to grow without having to somehow keep records so that you know all the potential people you are trading with, which means that the society can effecively grow infinitely large.
Isn't the value of cash dependant on inflation which does require some degree of record keeping? So - I'm not sure you can have infinitely large societies at least with the economic systems cash is based on. --RobHu
Maybe, but it's only one variable to track, and it doesn't vary particularly depending on the size of the market, so it's not a particularly harsh limitation. --Angoel
Cash is transparent. You can judge a transaction on its merits, without having to worry about direct knock-on effects.
Cash allows control. By imposing taxes on societal effects that you don't like, you can push people in the direction that you want them to go without the restrictions on innovation that you get by trying to impose direct laws, where people spend all their time looking for loopholes.
Cash allows comparison. "I will take course A" vs "I will take course B" can be decided simply by looking at which one is the greater number.
Which is a problem, because not everyone has the same root values. That drives positivesum trade - but the full knock on effects are not evaluated. Which means that the transparent thing doesn't always work.
It doesn't always work, acknowledged, but it works one hell of a lot better than all the alternatives. --Angoel
And the knowledgeless thing, whilst usually a good idea, does make certain classes of crime a lot easier. --Vitenka