A Noble Lie
Why it's OK to sin a little and "market-time"--provided you do it in a contrarian fashion.
A common nugget of wisdom passed down from on high to the masses is to "buy and hold," which really means several things: Set fixed allocations to stocks, bonds, and cash; dollar-cost average into the portfolio with periodic purchases; and, above all, stay the course. I tell investors to do these things all the time, too, because on the whole it's good advice.
It's also a noble lie, an untruth told to investors to keep them from hurting themselves.