The basic imperative...is to make sure that we do enough, long enough, so that you really have a recovery in place before we shift to restraint.
Implicit in this view is the assumption that that stimulus is a necessary ingredient for recovery. Yet before 1914, when there was no Federal Reserve and no Keynesian economics, the economy experienced recessions yet recovered about as quickly as since the advent of government stimulus efforts.
Thus Geithner's view is convenient for advocates of stimulus. If stimulus continues long enough, it will appear that stimulus worked. Then politicians can take credit for saving the economy, even if stimulus was unimportant or even counterproductive.