This a question from the Beyond Language written by Dmitri A. Borgmann.
Despite the martial-seeming title, this is a very peaceful problem, requiring calm reflection on your part to penetrate. (Military title? Why, yes! Shells are artillery projectiles, and a colonel is a commissioned army officer!)
Listed below are 25 twelve-letter words, grouped into eight catergories. Please examine the list attentively:
These 25 words have a special quality that sets them apart from most other twelve-letter words, but they possess that quality in varying degrees, represented by the eight subgroups into which they have been ordered. Group 1 is furthest from our ideal; Group 8 is the only one that realizes it fully. The six intermediate groups are successive stages of refinement on the road to our ideal, moving progressively closer to it.
We should like to see you duplicate our train of reasoning by giving us the correct answers to these five questions:
- What is the fundamental characteristic of all 25 words?
- Define the eight successive stages.
- We have chosen Stages 5 to 8 inclusive in accordance with a certain principle. We could have resorted to a different principle. Explain!
- The word "nonsiphonage" in Group 6 could have been placed in Group 5 with equal logic. Explain why.
- What is the significance of our title?