IN 1633, the Italian mathematician and astronomer Galileo was forced by the Catholic Church to renounce the scientific conclusions he had drawn from what he had seen with his own eyes. He had apparently seen past the faith of his day, making its doctrine obsolete and presumably putting quite a few jobs in jeopardy. So distressed was the establishment that Galileo was imprisoned for a time to keep him from influencing the public.

Robert J. Sawyer recounts a similar tale of an individual suffering because of the sometimes antagonistic relationship between science and religion. Far Seer (Ace, 257 pages, $5.99 paper) is the story of Afsan, a young astrologer from a distant planet whose observation of the stars through a newly invented "far seer" (telescope) sets him at odds with his culture's concept of itself in relation to the universe.

The significant difference between this hero and Galileo is that Afsan is a quintaglio - a dinosaur, according to Sawyer's description, not unlike a smaller version of what we know as Tyrannosaurus rex. Much of the book is made up of Sawyer's fascinating construction of a culture of intelligent dinosaurs who have successfully tamed their fierce territorial instincts in order to form a working society.

Sawyer's understanding of both our reptilian predecessors and of astronomy is considerable, and if at times his encyclopedic knowledge produces an encyclopedic writing style, he is careful not to overwhelm his readers. Far Seer entertains as a fantasy about an alien culture and as an exercise in world-building. But in its rendering of young Afsan's scientific zeal, and the price he pays for asking, "How do we know what we know?", the book winks at philosophy.