Commas to set off occupations?

Which is correct?
Bookmarklets are just one of the Web-related interests of ____________ Steve Kangas.
a. the mathematician,
b. the mathematician

Answer: b

Explanation:
You should only use a comma to set off an occupation if it uniquely describes the person following. If we said “the chief of Rocket Science at bookmarklets.com, Steve Kangas” we would need the comma — unless, at some point, they have a co-chief in that department, in which case we would revisit our sentence. However, because Kangas is not the only mathematician on the planet, we don’t need a comma in our sentence above.

Here are some more examples:

• the current pope, Benedict XVI
• the author Margaret Atwood (there are other authors)
• right-wing pundit Ann Coulter (there are other right-wing pundits)
• the president of the United States, Barack Obama

Incorrect use of commas is just one of the interesting discussions in Lex’s On Second Thought blog.

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