Learning Formal Logic the Natural Way

My ten year old, eight year old, and I have been slowly working our way through Harry Stottlemeir's Discovery for about two months (one discussion per week).  I continue to be amazed at the effectiveness of this simple story to communicate formal logic and critical thinking to my children. The best part is seeing them discover the logical principals for themselves, many times anticipating the discoveries made by the story's protagonist.

I asked the boys last week, who is the teacher in our weekly discussions?  They both immediately said that I was.  Then I asked them what I had taught them?  An interesting discussion ensued where they quickly abandoned the idea that I was the teacher and discussed the possibility that either the book was the teacher, the author of the book was the teacher, or whether they were the actual teachers.

The range of ideas in this very short text is vast, we only discuss a page or two per week.  You do need the teacher's guide (it seems expensive but is well worth it).  One chapter takes us 2-3 weeks to cover.  Here are some of the leading ideas from chapter four:

1. Are thoughts real?
2. What is ambiguity?
3. Vagueness
4. How thinking leads to understanding
5. The role of thinking in knowing oneself
6. Three types of quantifiers
7. Accepting reasons as proof
8. Harry's inference that Tony tried to hit him with a stone
9. What is accidental?