Nonsensical Logic

Charles Dodgson (Lewis Carroll), Mathematician and Author

On Charles Dodgson (Lewis Carroll), Mathematician, Logician, Deacon – 1832-1898

Charles Dodgson published creative, comical, and ciddy [sic.] writings under the name of Lewis Carroll, but Lewis Carroll published serious mathematical works under the name of Charles Dodgson, which I think he got from his parents. One of them was a book called “Symbolic Logic” (1896), a serious mainstream work on mathematical logic.

So without further ado, here’s his sytem of “symbolic logic” or “syllogistic logic”, which I’m sure is best explained by quoting one of the author’s own examples of the “sets of concrete propositions” capable of algebraic analysis leading to an answer or “conclusion”.

It IS a rather complicated one, admittedly, but with algebraic logical syllogisms it’s always best to start with a complicated one (don’t you find?) and work back:

(1) Every idea of mine [Charles Dodgson, that is], that cannot be expressed as a syllogism, is really ridiculous

(2) None of my ideas about Bath-buns are worth writing down

(3) No idea of mine, that fails to come true, can be expressed as a syllogism

(4) I never have any really ridiculous idea, that I do not at once refer to my solicitor

(5) My dreams are all about bath-buns

(6) I never refer any idea of mine to my solicitor, unless it is worth writing down

The universal given or subject of this is his idea; the algebra uses ‘a’ to mean able to be expressed as a syllogism, ‘b’ to mean about bath-buns, ‘c’ to mean coming true, ‘d’ to mean dreams, ‘e’ to mean really ridiculous, ‘h’ to mean referred to his solicitor, and ‘k’ to mean worth writing down

The answer (or logical conclusion or inference from these premisses) is of course:

All my dreams come true

You’d have got it sooner if you’d have had a logical piano, of course. Bath-buns, I must hasten to add, are tasty buns made in Bath, Somerset

Now you’ve mastered symbolic logic, see how simple his first example seems:

(1) Babies are illogical

(2) Nobody is despised who can manage a crocodile

(3) Illogical persons are despised

The mind fully trained in Dodgson’s symbolic logic will see instantly, even without doing the algebra, that

Babies cannot manage crocodiles

Which is indeed the correct answer or logical inference.

AVS