Introduction to Logic

Alice in Wonderland

Lewis Carroll included a number of instances of specious logical reasoning in Alice in Wonderland. The following is a famous example.

'[Y]ou should say what you mean,' the March Hare went on.

'I do,' Alice hastily replied; 'at least - at least I mean what I say - that's the same thing, you know.'

'Not the same thing a bit!' said the Hatter. 'You might just as well say that "I see what I eat" is the same thing as "I eat what I see"!'

'You might just as well say,' added the March Hare, 'that "I like what I get" is the same thing as "I get what I like"!'

'You might just as well say,' added the Dormouse, who seemed to be talking in his sleep, 'that "I breathe when I sleep" is the same thing as "I sleep when I breathe"!'

Alice seems to believe that the sentence pq is the same as qp; and this is a logical error, as made clear by the comments of the Mad Hatter, the March Hare, and the Dormouse. Clearly, Alice needs to sign up for Introduction to Logic.