Artistic criticism drives me nuts. If you want to understand why, click the link here:
http://www.somethingpositive.net/sp01142011.shtmlSee, what happened in that news post is what happens pretty often in artistic criticism - people who are not the artist say what they think the artist means, and get to have that taken as fact. But in most cases, the artist is not even alive to set the record straight as Milholland got to do here.
Here's the thing: you may think you know what Wilkie Collins meant. But unless you're getting it from something he said he meant in an interview or an essay or something, you're making it up. Extrapolation is just making it up with authority.