Who Stole the Tarts? Part II

"Now we have the jam back," said the King, "so you can make us some tarts."

"How can I make tarts without flour?" asked the Queen.

"You mean the flour was stolen?" cried the King.

"Yes!" said the Queen. "Find the miscreant, and take his head off!"
"Now, now," said the King, "let's not be hasty!"

Still, the flour had to be found. Sure enough, it was found in the home of the March Hare, the Mad Hatter, and the Dormouse, so these three were promptly arrested and tried.

At the trial, the March Hare claimed that the Hatter stole it. The Hatter and the Dormouse also made statements, but for some reason the statements were not recorded, so I cannot tell you what they were. Anyhow, as it turned out, only one of the three had stolen the flour, and he was the only one of the three who told the truth.

Who stole the flour?

(Source: Alice in Puzzle Land: A Carrollian Tale for Children Under Eighty by Raymond Smullyan)

First, note that the March Hare has somehow managed to avoid the executioner since the last episode, despite the punitive obsessions of the Queen.

But more to the point, there is only a single statement from the accused to evaluate here. That statement is: "The March Hare claimed the Mad Hatter stole it." This is necessarily false though, as "only one of the three had stolen the flour, and he was the only one of the three who told the truth". The only possible true statement of this form in this case is one of the accused saying: "I stole the flour." Accordingly, the March Hare is lying, and has not stolen the flour. Because of the content of the lie, the Mad Hatter cannot have stolen the flour either. From this we know that his testimony was dishonest, although not what it was. Given that this is a Carrollian story, it could be any number of false claims. But we can know, since neither of these other two stole the flour, that the Dormouse did, and made a true statement. Again, as this is a Carrollian story, we cannot know what the statement was. It may well not have been "I stole the flour"; it may have been irrelevant to the case entirely. But what we can infer from the sole statement made by any of the accused is that March Hare and the Mad Hatter have perjured themselves and the Dormouse is a thief.