
I just got involved in an internet freeforall on this issue, which I've wondered about over the years. Do you say "eggs, toast, and orange juice" or "eggs, toast and orange juice"? I have always put in the "extra" comma, as did Robert Nozick, author of
Anarchy, State,[sic] and Utopia.
One commenter spoke of being surprised when the last comma "came into use." Actually, I'm pretty sure The Oxford comma was the original system, gradually it has been disappearing. Take a look at any eighteenth century author, such as David Hume or Dr. Johnson. It's commas all the way down!