Originally Posted by Fat Abe
My brother-in-law, a full professor of literature, would deride the concept. A series, by definition, relies on recurring characters or themes. In terms of literary invention, this can be limiting, since the character's universe is proscribed and his actions are predictable. The professor claims this is a crutch.
How limiting is it really? Presumably your brother-in-law thinks the actions are predictable because the character is already established and the reader then "knows" that the character would never do certain things (and that if the author makes that happen she's doing so in reaction to existing perceived limitations.)
Whilst there's something in this I think it's a bit reductive. Long novels would suffer the same problem (character is well-established by half-way through.) In any case characters change and grow. Literally in some cases such as a series of novels where characters get older. Also if you choose to make your main character a coal-miner as opposed to a physicist then you've limited them. Even if your story is of a coal-miner inventing cold fusion it'll be a different type of story than if a physicist does so.
I read an essay a while back which I won't attempt to find but essentially it said that it's the limits that often create the art.