Wilkins, Dear and Darwin on species

A short while back I presented a quote by historian Peter Dear regarding Darwin's ideas about species. Of the quote I commented that it was "so wrong it is not even funny". Professor Dear took exception to that comment (especially after John Wilkins waded in with his view) and commented that "[i]f you want to show that I'm wrong about Darwin here,
give me some evidence from Darwin himself, rather than telling us what biologists and philosophers of biology believe nowadays."

Now John has provided the first of a series of posts on the development of Darwin's writings on species. Speaking of the quote by Dear that I originally presented, John notes:

[T]his is egregiously wrong. It is false in almost every important respect. And Dear is not alone in this sort of misunderstanding about Darwin and species. Something like it is stated authoritatively by almost every evolutionary textbook or book on species that appeals to history. It's time to defend Darwin, and look a bit more carefully at what turn out to be rather sophisticated discussions by Darwin for his time.