Chapter 6, Problem 78RE

Lewis Carroll The following exercises are from problems by Lewis Carroll. Write each premise in symbols, and then give a conclusion that uses all the premises and yields a valid argument. Source: The Complete Works of Lewis Carroll

Let u be “the writer understands human nature,” c be “the writer is clever,” p be “the writer is a true poet,” r be “the writer can stir the hearts of men,” s be “the writer is Shakespeare, ” and h be “the writer wrote Hamlet.”

(a) All writers who understand human nature are clever.

(b) No one is a true poet unless he can stir the hearts of men. (Hint: “(~a) unless b” ≡ a → b)

(c) Shakespeare wrote Hamlet.

(d) No writer who does not understand human nature can stir the hearts of men.

(e) None but a true poet could have written Hamlet.

(f) Give a conclusion that yields a valid argument.