The Norwegian man accused of killing at least 92 of his fellow citizens on Friday wrote that "once you decide to strike, it is better to kill too many than not enough, or you risk reducing the desired ideological impact of the strike".
If there is any consolation in this massacre, it is that deranged people like Anders Behring Breivik can't think straight. He had enough mental clarity to organise logistics but so little connection with the larger reality of humanity that he failed to understand his butchery would have the opposite effect.
Much media reaction to the tragedy has conflated the incident with the rise of far-right parties in Europe. The coverage implies that Breivik's attack is an extension of the trend and a frightening portent.
This is exactly wrong. His use of violence to pursue a "crusade" to halt the "Islamicisation [sic] of Europe" has discredited his cause, not advanced it. This is the worst thing that has happened to the far right in western Europe in years.
Breivik wrote in his rantings, which, for some reason, most media are dignifying with the title "manifesto", that he admired Europe's standout Muslim-baiting politician, Geert Wilders of the Freedom Party in the Netherlands.
Wilders opposes Muslim immigrants and wants the Koran and face-covering banned. His party won 15 per cent of the vote in last year's election, making it the third-biggest in the Dutch parliament.
But Wilders knows that any association with the mad butcher of Oslo is poison. He issued a statement on Breivik on Saturday: "I despise everything he stands for and everything he did."
Breivik once belonged to the far-right political party in Norway, the Progress Party. The party did well in the parliamentary elections of 2009. It won 23 per cent of the vote and entrenched itself as Norway's main political party.
But it did this by moderating its positions, sidelining members whose criticism of immigrants was seen as racist. It shifted emphasis to opposing Norway's overbearing welfare state.
Breivik, apparently frustrated, left the party. But when news of his atrocity hit, Norway's media quickly went to the Progress Party's leader, Siv Jensen, for her thoughts.
Jensen instantly denounced him: "The horrible and cowardly attacks we've witnessed are contrary to the principles and values underpinning the Norwegian society."
A Populus opinion poll in Britain early this year suggested that 48 per cent of Britons would support an English nationalist political party if it were not "associated with violence and fascist imagery".
Violence and extremism discredit everything they touch. They do not attract but repel people from political causes.
Breivik's own study should have taught him this lesson. He apparently studied his Islamist counterparts, al-Qaeda. He reportedly wrote: "Just like Jihadi warriors are the plum tree of the Ummah [Muslim community], we will be the plum tree for Europe and for Christianity."
He failed to notice that al-Qaeda's strategy and its tactics have failed, and failed spectacularly.
Why do terrorists use terror? Because they cannot win by conventional means. Terror is the tool of the weak against the strong. Al-Qaeda attacked the US in the hope that it would have two effects.
One, to diminish its enemy by provoking the US into a misjudged response. This succeeded. Not when the US invaded Afghanistan, which was a rational and well-supported response, but when it pointlessly invaded Iraq at enormous cost in blood and treasure and US credibility.
Two, al-Qaeda hoped to strengthen itself by winning support among the world's one billion Muslims. This seemed to have some initial success but has failed dismally. Ultimately, the mass of common Muslims were repelled by the use of violence against innocent people.
When an Arab uprising eventually occurred it was the so-called Arab Spring, where the people were inspired by hopes for democracy and dignity in a civilised society, not by savagery and extremism. When the US eventually killed Osama bin Laden this year, his death caused barely a ripple among the world's mainstream Muslims. He was a false prophet, roundly rejected.
There has been a rising tide of anti-immigrant, pro-nationalist sentiment in Western Europe in recent years. It has four striking features.
First, it has been quite successful at the ballot box. In the Netherlands, France, Denmark, Hungary and Switzerland, far-right parties have won between 10 and 30 per cent of the vote in national elections in the past four years. In Sweden, the far-right party went from zero to 20 seats in parliament with 5.7 per cent at last year's election. In Austria, the xenophobic Freedom Party won a quarter of the vote at provincial elections in the capital, Vienna, last year, a portent for the 2013 election.
Second, it has mobilised in opposition to Islam and Islamic immigrants and Islamic emblems but this is part of a wider theme about identity. "The key topics are always the same," said Uwe Jun of the University of Trier in Germany. "National identity, migration and a rather sceptical attitude towards Islam."
Third, it is remarkable that Europe has not seen a great deal more of this. The European Union project of dissolving borders and allowing free movement of people is a radical experiment in post-national social engineering. This plus a terrible financial crisis surely creates the perfect laboratory conditions for a nationalist backlash.
Yet, third, it has involved very little violence, till now. Europol this year reported that there were no right-wing terrorist attacks in Europe last year. There were, however, 45 left-wing and anarchist attacks and 160 separatist attacks.
Europe has to work out its problems but not Breivik's way. He might have known that "once you decide to strike", you damage the cause you are supposedly advancing.
But then again, how do you explain common sense to the criminally deranged?
Peter Hartcher is The Sydney Morning Herald's international editor.