My favorite steam-punk web-comic recently had a post about that: 2D Goggles OR The Thrilling Adventures of Lovelace and Babbage. (Based on real 19th C persons, mixing science, math, mayhem, and monkeys.)
image borrowed from 2D Goggles by Sydney Padua
The great detective novelist Dorothy Sayers also talks about the free-will of characters in her Mind of the Maker. She believed in authorial authority. "Too much attention should not be paid to those writers who say (holding one the while with a fixed and hypnotic gaze): 'I don't really invent the plot, you know - I just let the characters come into my mind and let them take charge of it.' Writers who work this way do not, as a matter of brutal fact, usually produce very good books." Read one of hers. Murder Must Advertise is a great Golden Age mystery, starring her detective Lord Peter Wimsey.