I read a blurb recently in a bookstore while on holiday, I decided not to buy it at the time and now I am regretting it. From what I remember there were two races living together in harmony. One race could use magic but not use mechanical devices (even have difficulty using latches on doors) and the other race cannot use magic but is gifted with mechanical skills.
May it be Darksword from Margaret Weis and Tracy Hickman?
Is a similar history where humankind is split in two: Magic users and non-magic users...