Despite the severe limitations religion placed upon the development of scientific enquiry, the Middle Ages did not produce a collection of notable and original thinkers who contributed to a gradual reawakening of rationality.  Together, these men led the way to the Renaissance and the full flowering of innovative science that followed.
Still wrapped up in the need to marry natural philosophy with theology, the thinkers of this period - who became known as the Scholastics, the most famous of whom were St Thomas Aquinas and Albertus Magnus - stuck to the traditional Aristotelian line, shunning experiment. However, they did champion the search for truth outside the limited realm of pure theology. Although they maintained a firm belief that man was the central object of Creation and that the universe was designed for man by God, they had progressed to the idea that the study of Nature and the physical world could lead to greater theological enlightenment. It was not until the deaths of Aquinas and Albertus Magnus (towards the end of the thirteenth century, some seventy-five years after Aristotle had been reintroduced into Europe) that the work of the great Oxford scholar Roger Bacon began to erode the restrictions of Scholasticism.
In some ways Bacon was a man born ahead of his time. Although he subscribed to many traditional beliefs of the Scholastics, he was the first to see the usefulness of experiment and he composed three far-sighted tracts - Opus Majus, Opus Minor and Opus Tertium - which outline his philosophy and his experimental techniques in a range of disciplines. This effort established Bacon's reputation for posterity, but did little for him during his lifetime. Viewing his work as anti-Establishment and its anti-Aristotelian elements as subversive, Jerome of Ascoli, General of the Franciscans (later Pope Nicholas IV), imprisoned him for life as a heretic.