Here’s a typically inane FDR quote:

No business which depends for existence on paying less than living wages to its workers has any right to continue in this country.

Taken literally, Roosevelt’s norm is superfluous: If you don’t pay your workers enough to keep them alive, your business won’t be around for long, will it?  

But the “living wage” is not about physical survival.  It’s a wage high enough to give workers what Roosevelt sees as a decent life.  And if a worker’s best option puts him above the line of physical survival
but below a “living wage,” FDR effectively says, “Give him a living wage, or give him death” – the social democratic equivalent of “Let them eat cake.”

P.S. In his better days, Krugman would have shared my scorn of FDR’s sound byte.  But now?