The Silent Tower, published in 1986, made a huge impression on me when I was a teenager, and I consider this book and its sequel to be major influences on me as a writer.
The world of The Silent Tower is post-medieval, specifically early industrial. We have guns and factories and steam power, and because magic is a threat to these new technologies–and wizards have historically been a destabilizing force in society, propping up evil rulers–it’s now outlawed for all practical purposes and restricted to an academic setting.
The church is powerful and considers magic to be sinful. They want to clip the wings of the wizards even more, which sets up an Enlightenment-era type conflict between religion and magic, with magic standing in for science or reason. A lot of modern urban fantasy novels present science (or “tech”) and magic as incompatible opposites, but I prefer Hambly’s interpretation, which is that science and magic are close relatives. In Hambly’s world, wizards must study the true nature of things in great detail before they are able to work magic of any substance, so they are all scholars and scientists at heart. Sometimes this deep study unearths truths that contradict church teachings, and then they wind up in conflict with the church.
Through it all, the hero Antryg Windrose wrestles with his conscience. He’s the most powerful wizard in the world. The use of his power is outlawed, and he understands perfectly well why it needs to be. Yet if he can use it to help people–shouldn’t he?