I always hated this argument. Its sort of like saying you need to take poison, so that if you ever get sick you can stop taking poison and possibly get better.

I always hated this argument. Its sort of like saying you need to take poison, so that if you ever get sick you can stop taking poison and possibly get better. 2ndly, interest rates were not very effective in these last recessions, the common metaphor is that its like pushing rope. So maybe its better for the fed to fight recessions with QE (or something else) and leave interest rates to 'fight' inflation.