We look at Medieval science as barbaric and backwards. We think of their culture as unwashed and religious based. They believed the Earth was flat. But they thought they were just as advanced and right as we see ourselves.
Every present science looks good to those living in that time period. Medieval scientists would have had many of the same thoughts as current scientists, but filtered through their culture, knowledge, beliefs, and science.
If you were writing Medieval science fiction what would it be like? How would you combine the Middle Ages into a story about cloning, for instance?