A few days ago, I wrote about how a categorical syllogism had kept me awake late at night. As a refresher, here is a Venn diagram showing the intersections of three terms:

The particular categorical syllogism in question is this: "If some men are doctors and some doctors are tall, does it follow that some men are tall?" My first thought was, sure it's possible that some men are tall, however it doesn't mandate that there is at least one tall man. Consider a society in which all the men are short and all the women are tall, but both short men and tall women can be doctors. I wonder if the author was trying to trick the reader into making the assumption that all doctors are men. If that was true, it would be a different puzzle.

Here's the diagram with terms replaced with specifics. We can't concluded anything about the intersection between Men and Tall.

If anyone (both of you reading this) want to praise me for nailing this problem, or ridicule me for getting it wrong, please do post a comment. I did a bit of searching on the Googles for information on the topic. I found some help in this article at PhilosophyPages.com, but not exactly what I remember from my college logic class textbook.