Invoked by a gloomy Moist von Lipwig in Raising Steam. Everything on the Discworld has its opposite. If the Hammer of the Gods has objective existence and may drop without warning into anyone's life, then there is also... and it's bigger. And it makes more of an impact. Moist is, figuratively, driving our ships to new lands. (ie, running the railway to Überwald). He fears the impact of large things cast down from above, especially in the narrow passes and ravines. And the Gods consider quantity is quality...