Stephen Jay Gould is one of the most popular writers on science today. It is a safe bet that his books are read and understood by more people than, say, Stephen Hawking's. This is primarily due to the fact that Gould's style is remarkable for its lucidity. Also, he has a way with words backed by a love of humanity which make one turn to his books again and again.

Gould is Professor of Zoology and Geology at Harvard. His best selling books include 'Ever since Darwin', 'The Mismeasure of Man', 'Wonderful Life' and 'Eight Little Piggies'. In the book under review, he continues with his obsessive theme that there is indeed no such thing as progress in the evolution of Life. There are millions upon millions of species of living things, divided into five kingdoms (not two as we have been brought up to believe), and our own species, Gould says, 'is a tiny twig, born just yesterday on an enormously arborescent tree of life that would never produce the same set of branches if regrown from seed. We grasp at the straw of progress (a desiccated ideological twig) because we are still not ready for the Darwinian revolution. We crave progress as our best hope for retaining human arrogance in an evolutionary world.' Strong words these. Yet Gould's theme is even broader than just taking a pot shot at the Western enlightenment and nineteenth century optimism.

The sub-title of the book is 'the spread of excellence from Plato to Darwin'. Darwinian revolution consists of the acceptance, from empirical evidence, of three things:

• The simple acceptance of evolution as an alternative to divine creation.
• The recognition of Homo Sapiens as only a recent twiglet on an enormous genealogical bush.
• Most important, the substitution of 'variation' for Platonian 'essence' as the central category of natural reality.

In order to emphasise his point, Gould advances a profusion of examples drawn from the world of sport (baseball) and medicine, the evolution of horses and the path of a drunkard! 'My central theme is that we can only understand trends properly if we map expansions and contradictions in variation among all items in systems, and cease to focus on the march of mean or extreme values through time.' Evolution of one species from another is by itself not a sign of progress but only evidence of the capacity of the species to adapt to changing local environments. Similarly, Gould goes on in an entertaining long chapter, the disappearance of the 400 hitter in baseball (Gould has an interesting first chapter in the edition briefing British readers on the rules of the game) is not because he has become extinct, but as a consequence of general excellence in play. Do not pull out trends from the Full House and spin theories but look whole and look close, he exhorts, .

Look at the Full house and rejoice at nature's infinite variety. We are not on top of the evolutionary heap but a latecomer to a world not made for us.

Gould goes on pitilessly, demolishing one pet theory after another, not put forth by us the common people, but by reputed life scientists. It is nonsense to say that the Age of Bacteria came to an end when other forms of life evolved. We are very much in the bacterial mode, he says and points to recent estimates which suggest that the combined 'biomass' of all bacteria on earth (and inside it) may outweigh that of all other forms of life.

Quite an iconoclast, you would say, and you will be right. Gould proudly proclaims the motto of his trade, that of the paleontologist (the fossil hunter), 'I break in order to reveal.' Surely Krishnamurti would have heartily approved! That takes me to the last question: If Gould is right in thinking that a claim for 'progress' even in the biological sense is not legitimate, what price 'psychological progress'?