Dr. Christian was chairman of the philosophy department when Philosophy, an Introduction to the Art of Wondering was published in 1973. The textbook was an instant best seller in academia worldwide because it profoundly changed the way philosophy was taught to students in their first confrontation with the discipline of philosophical thought. Christian’s textbook was not only well written but was the first to use a format that was unique to textbooks: Pithy margin quotes, humorous pictures and cartoons, color, and a layout that is now standard in textbooks worldwide.