The exponential growth in knowledge during the past 100 years has been so great that it is easy to feel overwhelmed. In science, disciplines that appeared coherent two or three generations ago are divided and subdivided, and subdivided again, as researchers specialise in ever narrower yet immensely complex niches. Although reductionism in science is often viewed with suspicion in the humanities, something analogous has happened there as a result of the increased production, if not over-production, of research. A few years ago at a conference on Victorian literature, I struck up a conversation with a fellow delegate who introduced himself as ‘a Browning man’, and sure enough there is a Journal of Browning Studies, edited from De Montfort University, Leicester. Yet Victorian literature itself would have been considered a sufficiently narrow field in the not-so-distant past.

It is as if we have erected a Tower of Babel, based on such a proliferation of knowledge that even specialists in adjacent disciplines have difficulty understanding one another. Under these conditions it would seem a futile as well as a thankless task to attempt a unified theory of knowledge, encompassing not only the sciences but also the social sciences, the humanities and the arts. Yet this is what Edward O. Wilson does in his book Consilience, subtitled The Unity of Knowledge, the central thesis of which is that ‘all tangible phenomena, from the birth of stars to the working of social institutions, are based on material processes that are ultimately reducible, however long and tortuous the sequences, to the laws of physics’ (1998, 266).

The book is a challenge especially to the social sciences and the humanities, for, Wilson argues, ‘the human species will make complete sense only when linked in causal explanation to the natural sciences’ (267). Understanding human nature and our place in the universe has traditionally been a function of religion, and religion is still the guide in life for very many, perhaps even a majority. Religion has not fared well, however, in its explanatory role when faced with the material universe revealed by science. As Wilson observes, ‘Theology, which has long claimed the subject for itself, has done badly. Still encumbered by precepts based on Iron Age folk knowledge, it is unable to assimilate the great sweep of the real world now open for examination’.