Facts and frictions

Scientists live in the world described by the Marquis de Condorcet in his Sketch for an Historical Picture of the Progress of the Human Mind. They really do believe that human powers of reason, working through science, can lead to ever-better material conditions, and most would go on to say (with Condorcet) that, thanks to reason and science, moral and social as well as material progress is made possible. They have, of course, many good - and they would claim objective - reasons for believing this and are baffled by the reluctance of many historians, sociologists and philosophers of science to agree with them. Admittedly this is usually a somewhat one-sided argument, since most practising natural scientists are far too busy doing their science to worry much about the views of nonscientists. But from time to time "dialogues of the deaf" occur that lead to the scientists retiring hurt, puzzled and often in a huff, determined to set up another initiative to improve the public understanding of science or to reform the school curriculum.

Michael Ruse's book explores, in the very special area of evolutionary biology, why and how this should be the case. It is a fascinating piece of historical and philosophical study that should also appeal to many practical scientists as well as to the historians and philosophers whom Ruse is ostensibly addressing. Not the least of the book's merits is that Ruse believes "that since science is the best kind of knowledge that we have, as a philosopher I take science as a model." He sets out to test several hypotheses of the relationship between notions of progress in society and in evolutionary biology and is admirably clear and transparent in laying out the evidence, as he sees it, and the nature of the conclusions that, in his view, follow. As in the best science, though, the evidence ("facts") and the conclusions to be drawn from it are kept quite separate; and any reader who does not agree has the wherewithal to reach a different conclusion. An added bonus is that the style is lively and the scholarly apparatus, though impressive, never intrudes.

Ruse first carefully defines how and when notions of Progress (using the capital P to denote application of the notion to society rather than to science) came to be generally believed by the post-Enlightenment intellectuals of Germany, France, Britain and then America, and how those rather different notions converged as 19th- and 20th-century biologists came to terms with Darwin's discoveries. A careful and thorough use of the literature is supplemented by revealing interviews with those of the dramatis personae still alive - and a surprising number still are. This strand in the book is a readable and very scholarly account of the painful birth and prolonged adolescence of evolutionary biology as a suitable and respectable subject for study by professional scientists. But there are those who, as Ruse points out, still doubt whether evolutionary biology has yet reached that state of maturity, or, indeed, if "a suitable and respectable subject for study by professional scientists" is a proper and sufficient description of maturity in a scientific discipline.

Much the most interesting and useful strand in this study is not the historical - good though that is - but the philosophical. Ruse uses his extensive knowledge of the historical development of evolutionary thinking to explore issues such as when and how does a scientific discipline become recognised, and how does a discipline in this professional sense differ from popular science, or a quasi- or pseudoscience like astrology? The study of what would become evolutionary biology started well before the word "scientist" was coined (in 1843) and certainly well before it was possible to earn a living as a professional scientist. The gradual definition of evolutionary biology as a science is therefore a good test case in trying to answer these kinds of questions. In addition, of course, there is, embedded in the early notions of "evolution", an implicit and often very explicit notion of social Progress.

Thus in trying to determine how and when evolutionary biology became defined, Ruse is forced to consider how and to what extent those who were struggling with such definitions were influenced by their own social circumstances, beliefs and agendas. This is very much a live issue among philosophers and historians of science, and they will be glad to have such a careful case study.

But there is more to this book than just another case study of the history and philosophy of an emerging scientific discipline. The scientific community is acutely aware that it is no longer trusted as it once was by politicians or by society. Surveys show that how citizens regard scientific "facts" depends, to an extent the scientific community finds alarming, on the nature of the employer of the scientist publishing the "fact" in question. Paul Dirac once famously pointed out, in a political context, that "electrons are neither red nor blue"; and good science has always been held by scientists to be equally free of political and other cultural influences or values. While this no longer seems to be a tenable proposition, few scientists would be prepared to go to the other extreme and subscribe to the belief that science is a social (or cultural) construct.

Ruse shows that notions of social Progress have always been present in popular accounts of evolutionary biology and are still present in today's school textbooks. He also shows, amusingly, how some of the professionals who in their professional work go to great lengths to disavow any notions of purpose, design or progress in biological evolution, nevertheless use such notions in their more popular accounts. He suggests that in most scientific disciplines the gradual expulsion of these cultural influences accompanies the professionalisation of the discipline in question and that a "mature" science is one in which these influences are minimal. Whether they can ever be nonexistent, at least in evolutionary biology, is uncertain, but Ruse usefully points out to evolutionary biologists the dangers they run in allowing the popularisers to put a Progressive "spin" on accounts of the science that they, the scientists, have so painfully constructed. This somewhat ambivalent relationship between popular science on the one hand and professional science on the other is one of the best things to come out of this analysis, and should be required reading for everyone involved in trying to increase the public understanding of science.

To sum up, this book shows how and why professional scientists, in the Anglo-Saxon tradition at least, came to believe value-free science was not only possible but necessary - and how tenuous the intellectual justification for that position has always been. We badly need other studies as careful and measured as this one, of other scientific disciplines, to see if Ruse's conclusions have general validity.

John Ashworth is chairman, British Library Board.