And then there is a third theory that states that, for every action there is an equal and opposite reaction, plus two pairs of demons who push with equal and opposite force on either side of the object experiencing the action. This third theory also fits the facts just as well as Newton’s. And then of course there is a fourth theory with three pairs of demons and a fifth with four pairs of demons and so on. We could also have variations of the demon theories with some demons pushing harder than others so long as their total effect is always equal and opposite. Then maybe some angels could be involved in all the pushing and pulling, working alongside the demons.
The point is that all the mechanical data that has ever been generated fits not only Newton’s parsimonious laws but also an infinite number of less parsimonious theories with additional entities. All of them are equally good at accounting for the facts; so we can not use empirical data to choose between them. They all make exactly the same predictions; so we could never devise an experiment to separate them. So why did Sir Isaac formulate his parsimonious laws and not more complex ones? Sir Isaac writes, “... we are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances”: Ockham’s Razor will explore the history of science as a process of simplification as more and more phenomena were embraced by simpler laws. The medieval universe with its angels and spheres were replaced by the modern solar system and the law of gravity. All the major advances have been accompanied by an Ockhamist reduction of complexity.
Ockham’s Razor will explore the role of the famous razor from Copernicus to Grand Unified Theories (GUT’s). The book will be threaded through with the life and times of William Of Ockham, who was a very interesting chap. Born in 1288 in the village of Ockham in Surrey (not far from my university), he became a Franciscan scholar who taught at Oxford but was summoned to Avignon to answer charges of heresy. His studies there led him to conclude that the pope himself was a heretic who should be deposed. He fled Avignon, along with a group of Franciscan rebels who were fighting the pope’s attack on Franciscan poverty (as portrayed in Umberto Eco’s Name of the Rose), and secured the protection of the Holy Roman Emperor. He continued writing polemical articles against the pope and defending the independence of secular authority. He died in Munich in 1437.
Ockham was one of the founders of nominalism which claims that metaphysical entities are merely words without reality. The principle was enormously liberating and threw a huge quantity of metaphysical lumber out of medieval philosophy and stimulated a new empirical approach to science. William of Ockham is therefore a hugely important figure in the history of science, philosophy, politics and the history of humanism, but is very little known outside of academic circles. Ockham’s Razor hopes to make the live and work of this remarkable man accessible to the popular science audience.
MLU: I very much look forward to reading your book. When will it be published?
JM: I’m still writing it, so hopefully sometime in 2008/09.
(Read more Machines Like Us interviews here.)