Lewis Carroll wrote about logic.

If you're really interested in the historical treatment of this, you might find the pdf at the following link useful:

https://archive.org/details/gameoflogic00carruoft
... and Dover published "Mathematical Recreations of Lewis Carroll" for a while.

Using the ISBN-10 ID:

http://www.isbnsearch.org/isbn/0486204928
This book doesn't exactly read like a "page-turner" novel. It is somewhat interesting from a historical, pre-computer age perspective.

Carroll alludes to the practical application of logic in contracts and laws.

Every time I try to read a bit more in this book, it is a chore, and I find something more interesting to do after a short while.

Also consider what it takes to construct a logic puzzle so that:

1. It has one and only one solution, and this property can be tested.

2. It doesn't require guessing at any point.

3. It has the "right" level of difficulty: Challenging enough to keep the interest of the best solvers and easy enough to encourage the relative beginners.

4. It has a sufficiently entertaining translation of math equations to "story" clues.

5. It can be stored, delivered, solved by users, and checked by a computer program.

6. It lends itself to machine generation to avoid the huge expense of manually constructing each puzzle.

If a given puzzle is just math, is it possible to measure the difficulty of a puzzle without a user-provided score or without a calculation of user completion rates and times? I.e, can the difficulty be calculated when the puzzle is constructed?

There are some interesting articles on the web that discuss this question.