Mike Fortun and Herbert Bernstein's book is a masterpiece - a particularly intelligent, useful and unusual book. It will constitute, I strongly believe, a solid mooring point to help us face the challenges and questions - scientific, philosophical and political - that the new century is forcing on us. The book is also refined and subtle enough to help us to avoid (and hopefully to forget) the crude, sterile and empty confrontation, known as the "science wars", that have raged over the last few years. This book must be read, reread and reflected on by everybody - for by arguing that science is a complex and messy business, the authors could have a major effect on how we think about science, about science as knowledge, and about science and politics.

Muddling Through is divided into two main parts. The first deals with the question that has so agitated and divided academia recently - namely, what is science and how does it work? The second part describes the authors' own experiences of various social debates about science.

In academic terms - I mean for scientists and also for historians and philosophers - this is a good and reliable book. Mike Fortun is a historian who is pretty familiar with today's science, while Herbert Bernstein is a quantum physicist who has taken seriously the task of studying what has been published by historians, philosophers and sociologists about scientific knowledge and its place in contemporary society.

However, the book is important not only because it is so deeply informed and of the highest quality, but also because it is so decisive in political and social matters. More to the point: it is decisive because it is both a "theoretical" book - dealing with ideas and words - and a book that relies on field work, particularly on militant action through the Institute for Science and Interdisciplinary Studies. The institute, which is led by the two authors, tries to act as a mediator when conflicts or tensions arise in society around science and technology.

Fortun and Bernstein view their ideas, concepts and ways of describing science not as mere words to throw back and forth in debate, but as tools to help them (and society) cope pragmatically with technology, and vice versa. They view their intellectual work as part and parcel of a larger enterprise of helping scientists to interact with society, and so try hard to be precise and to pay attention to everybody's wordings, claims and motivations. Every word and nuance matters tremendously.

In the first part of the book, the authors illustrate through different approaches - and without believing that there can be a unique, definitive and authoritarian answer - what it means when scientists practise "rationality", and what "experimenting" and "articulating" a proof imply. Using a series of metaphors to help the reader appreciate the many different aspects of experimentation, they suggest methods and tools that we can use to keep complexity at the forefront of scientific inquiry. For example, when considering the work done by Galileo, Darwin or the agricultural geneticists, they suggest graphical ways of representing the intricacies of theoretical and social practices. They suggest how one should judge results, and how to read and make sense of someone else's scientific claims. And they highlight the social connections and the cultural patterns that contribute to the making of science.

In the second, more novel, part of the book, the authors describe the role they have played in various scientific controversies, such as the decontamination of toxic wastes at military bases and current research into "quantum teleportation". Their aim is to help people talk to each other in situations where dialogue has previously seemed impossible. They also try to find common languages, presenting themselves as "translators" who allow scientists, business leaders, military engineers, politicians and laypeople to break out of deadlock.

Experts themselves, they try to share their knowledge and to have it reappropriated by as many people as possible. They refuse to simply assert truths dogmatically: rather, they try to "muddle through" with others, mobilizing all kinds of possible scientific knowledge, rationality and goodwill to support their arguments. Looking for what they call the "excluded middle" - for example by refusing to stick to the entrenched positions in the "science wars" - they value pluralism and responsibility, cultivating a demand for precision but also seeking unusual and new "assemblages" (of theoretical and practical positions, and of people and institutions).

Over and over again they emphasize the importance of science - but with two caveats. The first is to be "a responsible hole-ist" - in other words, to not always insist on being a reductionist. The second is: "Keep it complicated, stupid!" This comment refers to what historians often say about history and social sciences: namely, why should we make things simple (or even simplistic) when they are in fact complicated? Which, in the end, makes a lot of a difference.