The (almost really) Complete Works of Lewis Carroll

Symbolic Logic. Questions. I

Source: printed 1894

1. Explain the words “Logic” and “Proof”.

2. Why do we need Logic?

3. Explain “Proposition”. State the 3 ordinary forms, using x and y. And give an example of each kind, of your own invention.

4. Explain “Division”, and “Exhaustive Division”.

5. Break up each of the following Propositions under the 4 headings “Sign of Quantity”, “Subject”, “Copula”, “Predicate”.

(a) Some of us cannot understand Logic.
(b) I don’t like Logic!
(c) No cheap goods last long.

6. In Diagram yy’x, what Propositions would be represented by 0, 1, 01, 00?

7. Represent (drawing a diagram for each),

(a) No x are not-y.
(b) All x are y.
(c) Some x exist.
(d) Some books are bound and some are not. (x = “books”; y = “bound books”.)
(e) All my friends are unkind. (x = “my friends”; y = “kind friends”.)
(f) I have no friends.

8. State the Contradictories of (a), (c), (f), in Question 7.

[Feb., 1894]