I think it's more radical than that, money is trade. Simply: if a person acquired bread to pass on (for something else they wanted), then bread would be money.

I think it's more radical than that, money is trade. Simply: if a person acquired bread to pass on (for something else they wanted), then bread would be money. I think probably some animal species use money, on a rare occasion: if a monkey exchanges a grape for sex, and the money with the grape exchanges the grape, the grape is money. It might be that amongst other animals, that ability to see the future-value-to-others of grapes is very very limited. So other animals dont keep grapes around. If they did, grapes would be money. That the value of a grape depends, like that of a dollar, on what we expect another to take for it -- this makes it seem mysterious -- because we ourselves are distrustful of the future, and of having-what-you-dont-need. I think this is an animalistic impulse: its a kind of paranoia about the behaviour of others. This is at the heart of why people use "collective delusion" and the like. There's something, in that sort of person, which views depending on the future behaviour of others with paranoid suspicion.