1. Willie Nelson’s song “I’d Have to be Crazy” contains the line

I’d have to be crazy to fall out of love with you.

Based on that hypothesis, he asserts

The place where I hold you is true, so I know I’m all right.

Is this a logically valid argument? That is, is still being in love a logically sound reason for Willie to assert he’s not crazy? Why or why not?

2. The King James translation of the Bible contains the following logically nontrivial statement:

Every one that hath forsaken houses, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for my name’s sake, shall receive a hundredfold, and shall inherit everlasting life. [Matthew 19:29]

Write a sentence which gives the negation of that statement.

3. You are checking to see if it is always true that people who are taller than average dislike sitting in low chairs. In each of the following situations you have partial information. In which situations must you investigate further to make sure your premise is not invalidated, and what piece of information must you find out in each of those cases?
     a) The subject is 6′6″ tall.
     b) The subject is 4′11″ tall.
     c) The subject complains a lot about the low chair.
     d) The subject happily settles into the low chair.