The judges presiding over the trial of Anders Behring Breivik in Oslo are due to give their verdict tomorrow. It is likely, though by no means certain, that Breivik will be judged to have been criminally insane when he murdered 77 people last year, and sentenced to compulsory psychiatric treatment. The only other possible outcome is that he be judged criminally responsible for his acts and condemned to life imprisonment. The difference between the two verdicts is in all practical senses minimal: in neither case is he likely ever to walk free again. But in symbolic terms the difference is huge. It represents, in effect, a judgment as to whether Breivik’s actions have political meaning or not.

When the state prosecution was first asked to present its charges against Breivik late last year, it seemed clear which was the more appropriate of the two outcomes. According to the psychiatric profile drawn up by Synne Sørheim and Torgeir Husby, two of Norway’s leading forensic psychiatrists, Breivik suffers from paranoid schizophrenia. But when Sørheim and Husby’s report was leaked to the press in December, it caused a public outcry. Three out of four Norwegians think Breivik should be condemned as guilty, and to be punishable a suspect must – under paragraph 44 of the Norwegian criminal code – be considered sane at the time he committed his crimes. Breivik’s lawyers also rejected the report’s conclusion, since he wishes to be seen as a political ‘martyr’ and for that he must be held to be sane. The court called for a second psychiatric report.

Rather than confirming Sørheim and Husby’s diagnosis, however, the second pair of psychiatrists, Agnar Aspaas and Terje Tørrissen, considered Breivik capable of empathy and rational thought, if narcissistic and possibly bipolar.

The trial was never going to be about guilt or innocence or even the magnitude of the offence – Breivik confessed to his crimes openly and in disturbing detail, both under interrogation and in the courtroom. But the logjam between the two psychiatric reports came to dominate the trial in a way nobody anticipated, much less desired. Aspaas and Tørrissen were willing to admit that a diagnosis is no more than a classificatory interpretation of an individual’s state of mind, but Sørheim and Husby refused to give an inch. And their refusal to accept any measure of doubt with respect to their diagnosis ultimately nixed all serious consideration of factors other than Breivik’s psychological condition: factors such as his political views, for example.

The result was to turn Sørheim and Husby into ‘judges without capes’, as one Norwegian editorial put it, since in light of the second report, their refusal to countenance any doubt as to their own diagnosis makes it hard for the judges – in a system where any reasonable doubt will be interpreted to the benefit of the accused – to reach a conclusion other than that Breivik acted with diminished responsibility. Given Breivik’s own wishes, that could be read, somewhat narrowly, as a victory for the prosecution. But it flies in the face of the more basic sense of justice that many Norwegians have looked to the trial to provide.

Perhaps more importantly, it raises questions about the law’s confidence – particularly Norwegian law, which has a distinctly medicalist tint – in the ability of psychiatry to parse juridical truth from psychological speculation. Contrary to the general tenor of the trial, this is very much a political question. And it warrants asking, on these grounds, quite why it was that psychiatric considerations came to dominate the logic of prosecution and defence alike, such that the testimony of police officers, of experts on political extremism, and of far right members of the blogosphere to which Breivik contributed, was listened to but in the main politely ignored.

Norway was rightly praised last summer for not automatically assuming that the terror of 22 July was the work of Islamic extremists. But whatever judgment is returned this week, it is hard to imagine that, if it had been, questions of politics, much less religion, would have been quite so easily cast aside in the trial, or that the court would have tied itself in such knots trying to get to the bottom of a psychological rather than a political profile of the terrorist.