From a reader. Apparently, the Cicero quote is a fake. He writes:

’he Cicero quote is almost certainly apocryphal– a discussion on snopes argues that it originated in A Pillar of Iron (1965), Taylor Caldwell’s fictionalized account of the life of the senator. (In fact, [John H. Collins, Professor of History at Northern Illinois University] noted that it was on page 483 of the edition he had in hand.)

I am grateful for the correction. I still believe that we haven’t learnt much. In fact, some knowledge about sound fiscal policy may have been destroyed.