Certainly gold and silver prices fluctuate versus currencies and commodities just like everything else on the market. The argument against fiat is that having a currency pegged to gold and silver makes your currency much more stable and decentralizes the control of the currency. Fiat currencies are controlled by the central bank which can inflate at will ruining your savings and destroying the purchasing power of the dollar.
For example, here is a chart of the purchasing power of the US dollar from 1792-2011. Note the dotted lines where we went off "hard currency".
http://www.wealthwire.com/news/inflation/773
For example, here is a chart of the purchasing power of the US dollar from 1792-2011. Note the dotted lines where we went off "hard currency".
http://www.wealthwire.com/news/inflation/773
Stuff like that is misleading. There is FAR FAR more to the monetary control debate than "zomg the dollar is worth only a fraction of what it was!!!" Charts like that designed to get an emotional reaction out of people that don't think. Without even getting into details, just consider for a second that in 1900 people worked for pennies an hour. So, yes, the dollar was worth more, but that's only a tiny part of the story. You can't just look at relative value of a dollar and ignore all other factors.