Earlier quoted context omitted.
Money can be destroyed by unpaid debts. The past bubble originated from money creation by loans. Read Wikipedia article on fractional reserve banking http://en.wikipedia.org/wiki/Fractional-reserve_banking
The money was not destroyed, the person who took out the loan has it. Maybe he spent it, so whoever he gave it to has it, but it was not destroyed. Fractional reserve banking is a lovely canard that is trotted out constantly, but it is not the monster the internet makes it out to be. Don't believe popular logic just because it's repeated over and over. Fractional reserver banking, at it's core, is a way of converting…
If the bank is unable to reclaim the physical money backing the loan, for example by foreclosing and reselling or having and investor cover the loss, the physical money would be destroyed. You see this happening now with banks raising money by selling equity. In other words if the loaned money bought things with no value or less value than paid then physical money is destroyed. If the loaned money buys things with more value than loaned then physical money would be created. This is simplistic description but I think accurate.
There has to be a mechanism for money and value creation and destruction. Money cannot be conserved. There is clearly more value/wealth and money in the world than 100 years ago.