Hitler's Scientists: Science, War and the Devil's Pact By John Cornwell

The collusion between scientists and Nazism raises questions about the nature of science itself, says Matthew J Reisz

It is tempting to turn the story of "Hitler's scientists" into a morality play. On the most comforting view, bad regimes make for bad science. Post-war clichés, writes John Cornwell, saw British scientists as "ingenious boffins, effortlessly superior, and modest with it", while their German counterparts were "at best, brutally efficient and militarised... at worst, monstrously sadistic". Real scientific progress, it is argued, requires a climate of scepticism and intellectual freedom utterly unlike that of the Third Reich.

Other moralists point to the willingness of many German scientists to carry out ghastly experiments on captives, promote racial agendas and denounce Jewish colleagues as evidence that science itself is tainted. Allied nations had few scruples about signing up people like Werner von Braun, who became head of the American space programme after using slave labour for much of the initial Research and Development. (Since he had a brief spat with the SS, he was conveniently able to claim that he had never been a real supporter of the regime.) But where does that leave the morality of the moonshots?

Many of the most interesting issues concern the career of Werner Heisenberg, whose enigmatic behaviour was explored in Michael Frayn's award-winning play Copenhagen. Were he and his team simply too incompetent to build a German atom bomb? Or did they, as some have claimed, sabotage the project on moral grounds? Hiroshima, on this paradoxical and offensive view, proves the Allies were worse than the Nazis.

It is part of Cornwell's purpose in this hugely ambitious book to ask moral questions while avoiding facile moralising. We can and should recognise the real achievements of the Third Reich's cancer-prevention campaign, even as we deplore the appalling films which depicted cancer cells as Jews overwhelmed by X-rays in the guise of stormtroopers. If we really want to pass judgement on someone like Heisenberg as an individual, we need to know a good deal about wider Nazi technological and educational programmes, institutional pressures on scientists, levels of permitted dissent, and so on. And perhaps we should also compare the behaviour of British and American scientists of the same period, not to mention those operating in the highly militarised environments of the Cold War and since 9/11.

This is a lot of ground to cover in a single book, and it is sometimes hard to keep in focus its sheer range of vivid material. Cornwell ends with some rather utopian policy proposals and occasionally falls back on obvious points like the fact that "great talent in physics is not a necessary, still less a sufficient, basis for moral and political integrity". Yet he lets us feel what it was like for ambitious scientists, many of them fairly apolitical, to be forced to sign oaths of allegiance or give the Nazi salute. And he illuminates the differences as well as the uncomfortable similarities between fascist and democratic regimes as "research environments".

Nazi Germany was run on the Führerprinzip (leadership principle), which in practice led to a number of viciously competitive bureaucracies working on the same tasks. Hitler knew little about science, acquired a few crackpot ideas from equally ignorant cronies and believed toxic gun-cleaning fluid made a good stomach medicine. Yet his insane self-confidence often led him to bombard the experts with half-baked theories, as when he harangued an admiral on the shape of fish as a model for boat design. "He found it difficult," writes Cornwell, "to bridge the gap between his acts of will, his fiats and the technical feasibility of his decisions."

Himmler was worse, bringing "a lethal mix of power, fear, cruelty and dilettantism" to research programmes devoted to left-handedness, the Earth's original second moon or the red horses mentioned in old Norwegian poetry. Most extraordinary of all, Goering put a buddy called Colonel Udet in charge of the technical direction of the Luftwaffe, even though he was a former stuntman without any relevant qualifications. His level of competence can be gauged by the fact that he objected to research on radar because, if it worked, "flying won't be fun any more."

Equally crucial to eventual Allied victory was cracking the Enigma code. Bletchley Park may seem amateurish in retrospect, but it was far more efficient than Germany's system of seven rival code-breaking organisations. When resources were briefly lacking, Churchill sent a memorandum reading "ACTION THIS DAY".

What happened at the end of the war is less reassuring. When 10 leading German physicists were held at Farm Hall near Cambridge and one wondered whether the place was bugged, Heisenberg dismissed the idea: "I don't think they know the real Gestapo methods." Yet they were, of course, being recorded by security services keen to discover their level of bomb-making expertise, and whether they might be willing to sell it to the Russians.

All this remained a secret for half a century, but Cornwell makes excellent use of the transcripts. One of the results of confinement, he suggests, was that the scientists got an opportunity to work out a coherent cover story which edited out their own complicity in Nazi evil - a cover story which has proved hard to shake.

So where does this leave someone like Werner Heisenberg? He was undoubtedly a great theoretical physicist, a German patriot, "morally and politically obtuse", but no Nazi. He refused to join the Party, had close relations with several Jewish colleagues and saw his career stall when he was attacked for it. (He only got back on track by asking his mother to intervene with Himmler's mother.)

This amounts to a portrait of someone who was neither an out-and-out villain nor "the brilliant hero who deprived Hitler of the atom bomb". Hitler's Scientists describes a few scientific heroes and rather more authentic monsters, only too happy to curry favour by savaging Einstein or accepting posts in concentration camps. But most of its characters are much more ethically ambiguous. One may miss the easy certainties of more polemical texts, but this is a gripping study in moral complexity.