It may not seem like the fate of the planet rests on whether you need a comma in a series before the conjunction that joins the last two items, but then you did not go to the same graduate school or have the same week I had. I do recall blithely leaving the comma out on such occasions before numerous professors red-inked me out of that habit and I began to put commas everywhere, just in case. I had forgotten that there is even credible dissent on this point until I received bruising feedback on a critical e-mail and found my own peeps would not back me up.
First, here is the email. The context of this email was a very lengthy and repetitive exchange over what started as a simple request passed on from my clients to a co-worker. After confusion set in as to the nature of the exact task at hand, I compressed and summarized the discussion into (I thought) a more digestible set of bullet points and rebooted the chain. In the midst of my summary, I wrote (names changed of course): “Rupert, Misha and Ferris do not need to be involved any further in this conversation.” To my horror, I received an email from Rupert’s colleague taking me to task for cutting Rupert out of the meetings when Rupert was the source of the request that began the trail. I managed to steel my nerves and reply simply: “I am asking that Rupert leave Misha and Ferris out of the conversation.”
When I discussed this story with others, I pointed out that had I wanted to get rid of Rupert I would have put a comma after Misha’s name. It should have been apparent that I was addressing Rupert, not including him, because, after all, one puts a comma before “and” in a series of three or more. Right? My audience was incredulous. More to the point, I have been advised a colon would have been better than a comma after Rupert’s name (I can see that). A little research on the web found that the matter is up in the air to the point that I definitely had no right to expect Rupert and colleagues to understand my request. The whole episode put me in mind of the book ‘”Eats, Shoots and Leaves“, whose title is a clever commentary on my dilemma and whose message about the importance of good punctuation was never clearer to me.