Earlier quoted context omitted.
There is a great post on r/bitcoin on this topic by Erik Voorhees. He talks about the value of network which gives bitcoin its value. A great read: http://www.reddit.com/r/Bitcoin/comments/1rxmk3/my_open_lett...
Networks come and go. Hard money, however, can still be found on hundred-years-old wreckage somewhere under the ocean.
But there are plenty of other forms of money that have vanished, from stone wheels, to shells, to papers. And all of those would be considered hard money.