[ddt]

Partly, it has to do with the role of the church pre-enlightenment. The modern secular university didn't exist in the 13th Century. The concept of a teaching body that granted degrees, certifications, and did research was barely off the ground with things like the University of Paris and the Thing Which Would Become Oxford University. The scientific method didn't exist as any formal process. If you wanted to spend your life thinking, you didn't have too many vocational options outside of the church.

As to his role as a "scientist, philosopher, mathematician, theologian", that's more a projection of modern concepts onto a historical figure. There wasn't nearly as much siloing of various intellectual pursuits. There were just secrets of Nature to be discovered, and people looking to discover them.

[pizza]

Do you know of any good books about this "projection of modern concepts onto a historical figure" thing? It's something I've been thinking about for a while.

[ddt]

I haven't read any books specifically on this topic, but it's a fairly common thing in non-academic (and sometimes academic) discussions of history. There's a subreddit, http://reddit.com/r/badhistory, that spends a lot of time picking apart bad historical arguments from around the web. Just as often as not, I'd say, the issue with the history is just as much trying to apply modern morality and societal norms to a culture completely removed from the modern day as it is factual inaccuracies.

It's not exactly a rigorous explanation of the phenomenon, but it is a good set of case studies.

Also, it should be noted that using modern concepts in a historical setting is not always "wrong" or "bad history". It's pretty clear the author of this article chose to describe Grosseteste the way they did to simplify his work for a broader audience.