Summers on animal spirits and confidence

"The central irony of financial crises is that while it is caused by too much confidence, too much borrowing and lending, and too much spending, it can only be resolved with more confidence, more borrowing and lending, and more spending." Lawrence Summers FT 10/24/11

This is a very clear statement on the importance of confidence and credit when addressing a downturn in the business cycle or a financial crisis.