Evaluate the following reductio ad absurdum arguments by asking the above three questions.
1. Claim to be Refuted: Even the worst of enemies can become friends. Reductio: If people are enemies, then they are not friends. If they do become friends, then they are not enemies. So it's absurd to think that enemies can be friends.
2. Claim to be Refuted: This ball is both red all over and green all over.
ReDuctio: If it is red, it reflects light within a certain range of wavelengths. If it is green, it reflects light within a different range of wavelengths. These ranges do not overlap, so it is absurd to think that anything can reflect both kinds of light. Thus, a ball cannot be both red and green all over.
3. Claim to be Refuted: Most children in Lake Wobegon are above average (in intelligence).
REDuctio: If so, the average (intelligence) would really be higher than it is; and then it would not be true that most children in Lake Wobegon are above the real average (intelligence).
4. Argument to he Refuted: Your brain is mostly empty space, because the subatomic particles in it are very far apart.
Reductio: That's absurd, because my brain is solid, and it works pretty well.
5. Claim to be Refuted: Some things are inconceivable.
Reductio: Consider something that is inconceivable. Since you are considering it, you are conceiving it. But then it is conceivable as well as inconceivable. That is absurd. So nothing is inconceivable.