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Explanations edited by John Cornwell, Oxford University Press, £18.99, ISBN 0198607784

EXPLANATIONS are the stock-in-trade of scientists. Those who come up with really good ones can expect to win the plaudits of their colleagues, and the rest of us may sometimes share the satisfaction of seeing a piece of the cosmic jigsaw puzzle fall into place, even if we do not always understand the details.

Yet what do we really mean by an explanation? John Cornwell, director of the Science and Human Dimension Project at Cambridge University, decided to ask some distinguished scientists and philosophers what they mean by it – and, perhaps inevitably, the result is a curate’s egg.

The opening chapter is a pretty demanding tour d’horizon in which philosopher Peter Lipton reviews some candidates for features we should demand of anything that claims to be an explanation. He believes the essence lies in causal links – that is, explanations should allow one to infer one thing from another. Or at least, I think he does; as with several other essayists, Lipton clearly holds precision of expression above clarity. The best contributions come from practising scientists, who make a better fist of explaining why anyone should care about the concept of explanation. Cosmologist Martin Rees and anthropologist Jack Goody show how their fields have been affected by changing fashions in explanation, while physicist John Barrow considers the impact of Gödel’s incompleteness theorem on attempts to explain all physical phenomena.

Judging by their contributions, life scientists are especially troubled by the issue of what should pass as an explanation, with plant scientist David Hanke railing against the fashion for casting all biological explanations in terms of purpose and function. Hanke singles out Richard Dawkins for promoting this teleological view of biology, especially among young researchers. The benefits of avoiding the one-explanation-fits-all approach are highlighted by Peter Atkins, who shows how chemists have benefited from their eclectic approach of picking different modes of explanation as the need arises.

In the end, it’s hard to avoid the impression that scientific explanations are like obscenities: hard to define, but pretty obvious when you meet them.