The paper money clearly does not respect ANY of these principles nowadays. The FED can print (and does) as much as they want to buy back toxic assets (remember the Krugman clown advising after the Net bubble in 2001 that we should create a housing bubble to stimulate the economy ? That really worked well for everyone, did it not?). The US Dollar is constantly losing value versus Gold since its parity was dropped for good in the 70s, and now you have such a galoping inflation than looking at movies 30 years ago make you feel old: then the bad guys were asking for "a million dollars" as something highly valuable/desirable, while nowadays if you do not cross the billion mark it is not considered as much anymore (Austin Powers made this very good point in a clever way).
Why do you think China is buying all the Gold it can currently to replace its stinky dollars?
Currency is based entirely on concensus. Anything (ivory, sheep, even bits of paper) could be currency; the only requirement is that there are people willing to use it as a basis for trade. In other words, it doesn't really matter if you don't believe in paper currency as long as everyone else does.