carrot and the stick, the

Reward and punishment. The term alludes to dangling a carrot in front of a horse or donkey to get it to move, and threat- ening or beating it with a stick.  An essay about philosopher John Stuart Mill explains that for Mill’s father, “Praise and blame . . . were to man what car- rots or sticks are to a horse or an ass . . . It was this carrot and stick discipline

to which Mr. John Mill was subjected.” The term dates from the late 1800s.