"A mule aint like a horse," says Uncle Parsham (11.41).
Now, we at Shmoop aren't experts on mules and horses, but we're going to agree with Parsham: a rectangle is not a square.
So if a mule's not like a horse, what is it like exactly?
Well, according to Parsham, when a horse gets a "wrong notion" in his head, all you have to do is swap out the old idea for a new one. Easy, you brainwash it. But a mule is different. A mule can't be so easily brainwashed: it will hold two notions in its head at the same time, and the only way to change one of these notions is to act like you believe the mule thought of changing its own mind first.
Wait, so it's like Inception? Yes. But for mules. You plant an idea in the mule's mind, but you make him think it was his idea in the first place. Okay, got it, sweet.
"That's why you dont pet a mule like you do a horse: he knows you dont love him: you're just trying to fool him into doing something he already dont aim to do, and it insults him," Uncle Parsham warns (11.41).
So mules represent power, intelligence, and sagacity, and they play an important part in the story. Ned once taught mules to race like horses, and mules help free the Winton Flyer from the mud that threatens to engulf it back in Hell Creek.
Mules are also known for their stubbornness, much like Boon. Both get ideas in their heads and latch onto them; just think of Boon's desire to drive Boss Priest's automobile and get with Miss Corrie. However, though mules and Boon cannot be so easily swayed, they can be tricked into acting in ways contrary to their intentions. For instance, Butch angers Boon in such a way that Boon's decision to beat the cop feels like his own, even though it has been incited by Butch.
Like horses, mules are essential parts of the Southern landscape, representing yesterday's way of life. Though brilliant and useful creatures, they are just another entity of the past that will be wiped out by the time adult-Lucius tells his story to us.