Complexity and theology
Both complexity and order in the natural world have been cited as evidence for an intelligent creator (compare page 1195). Early mythologies most often assume that the universe started in chaos, with a supernatural being adding order, then creating a series of specific complex natural systems. In Greek philosophy it was commonly thought that the regularities seen in astronomy and elsewhere (such as the obvious circular shapes of the Sun and Moon) were reflections of perfect mathematical forms associated with divine beings. About complexity Aristotle did note that what nature makes is "finer than art", though this was not central to his arguments about causes of natural phenomena. By the beginning of the Christian era, however, there is evidence of a general belief that the complexity of nature must be the work of a supernatural being—and for example there are statements in the Bible that can be read in this way. Around 1270 Thomas Aquinas gave as an argument for the existence of God the fact that things in nature seem to "act for an end" (as revealed for example by always acting in the same way), and thus must have been specifically designed with that end in mind. In astronomy, as specific natural laws began to be discovered, the role of God began to recede somewhat, with Isaac Newton claiming, for example, that God must have first set the planets on their courses, but then mathematical laws took over to govern their subsequent behavior. Particularly in biology, however, the so-called "argument by design" became ever more popular. Typical was John Ray's 1691 book The Wisdom of God Manifested in the Works of the Creation, which gave a long series of examples from biology that it claimed were so complex that they must be the work of a supernatural being. By the early 1800s, such ideas had led to the field of natural theology, and William Paley gave the much quoted argument that if it took a sophisticated human watchmaker to construct a watch, then the only plausible explanation for the vastly greater complexity of biological systems was that they must have been created by a supernatural being. Following the publication of Charles Darwin's Origin of Species in 1859 many scientists began to argue that natural selection could explain all the basic phenomena of biology, and although some religious groups maintained strong resistance, it was widely assumed by the mid-1900s that no other explanation was needed. In fact, however, just how complexity arises was never really resolved, and in the end I believe that it is only with the ideas of this book that this can successfully be done.