So what exactly is natural?

This is not just a book about one awkward concept. It is a wide-ranging discussion of a much bigger matter - the question of what explanation is and how it works. As John Habgood points out, the different meanings of "nature" have become linked to rival abstractions - conceptual schemes used by competing studies that seem to divide up our world into separate and often warring provinces. The frontiers of these intellectual strongholds are often drawn at the edge of what is taken to be natural. But, as he says, these maps always distort the evidence: "All explanations, at whatever level, to a greater or lesser degree, entail some element of human construction, and all confront us with an element of givenness, against which our ideas about reality have to be measured."

This element of the given is what we call nature, drawing the line in different places for different purposes. Our various intellectual disciplines then tend to encamp themselves on one side or the other of the divide, but constantly try to extend their empires by applying their chosen patterns to subject matter that does not suit them.

This imperialism cannot work because different areas demand different concepts. The 17th-century's ambitious hope of finding a single comprehensive formula that would map the whole of reality was an empty one, and the mind-body dualism that succeeded it has proved to be no better.

Accordingly, as Habgood says: "The classic dualism between nature and culture may have to be redefined. It may have to be conceded that a God-like perspective on the natural world is not possible, precisely because we are not gods. Indeed it may be that theology's main contribution to the discussion is to go on offering reminders of this fundamental truth."

In a series of fascinating discussions, he shows how the notion of the given has been repeatedly distorted. That distortion is, of course, what has led constructivists to outlaw it altogether, claiming (not very convincingly) that we live in a world entirely of our own creation. Habgood suggests that the main trouble here has arisen from a notion of givenness that was unrealistic because it was too static. In politics, this bias meant that the natural order was simply equated with the status quo. In biology, it meant the immutability of species and, in religion, it has been the root of fundamentalism. If we want to avoid mistakes of this kind, what we need, says Habgood, is to realise that "by itself, givenness is too static a quality to convey the dynamism inherent in nature as commonly experienced... This sense of 'becoming' tended to be ignored both when theologians envisaged nature in its present form as a once-for-all creation by God and when the scientific image of nature as a vast predetermined machine was in the ascendant. Nowadays, we know that the machine was no more than a convenient human constructI The natural world is one long history of change."

This book gives a shrewd, lucid, balanced account of the difficult problems that radiate from the notion of nature and shows how their complexity really does call for new and imaginative solutions.

Mary Midgley was formerly senior lecturer in philosophy, University of Newcastle upon Tyne.