What literary element is a stick behind stubborn mule?

This is a bit of a tricky one, as it's not a single literary element but rather a metaphor for a common conflict within literature.

Here's the breakdown:

* Metaphor: The "stick behind a stubborn mule" isn't literal, but represents a situation where *force or pressure is used to motivate something or someone who is resistant to change*.

* Conflict: The situation itself highlights a common type of conflict in stories: man vs. man, man vs. self, or even man vs. nature, where one force tries to overcome the other.

So, while "stick behind a stubborn mule" isn't a singular literary element, it embodies the concept of using force to overcome resistance, which is a very common theme and conflict in literature.