This is a sequel to one of my favourite books, Soul of a Robot, and manages to be every bit as enchanting as the first but with added analysis of what consciousness is, what it means to be human, and what the difference is between being conscious and being simply a constructed being. Absolutely brilliant, and Bayley's workman-like but reliable prose really works for me.

Why Bayley is not yet regarded as one of the most important SF writers of the last century is still a mystery to me. ( )

The Rod of Light is Bayley’s sequel to his SF classic, Soul of the Robot. It picks up with Jasperodus, the robot who wanted to have consciousness, visiting the last Zoroastrian temple. There the priest expounds on the nature of the cosmic struggle between light and dark, spirit and matter. He makes it pretty clear that for followers of Ahura Mazda’s light, robots are from the dark.

The dialectic of dark and light permeates the action-filled story that follows. Jasperodus and other free robots are marked for destruction (can artificial minds die? are they even alive?) by the Bogor Empire. Meanwhile a group of super-intelligent robot scientists are developing their own technique for instilling robots with a true sense of self-awareness, a sentience beyond mechanical mimesis, a soul. Jasperodus is caught between his own desire for self-preservation, the Bogors’ hatred of robots, and his revulsion at the soulless methods of the robot scientists. Souls are granted freely to humans, but robots acquire them at a steep price.

http://fireandsword.blogspot.com/2007/11/rod-of-light-by-barrington-j.html