It’s not quite right to say the suspect charged with killing 50 Muslims in Christchurch, New Zealand, last week was “crazy,” or “mad.” He was not “insane.” He had thought quite clearly about why he did what he did and what he hoped to accomplish, captured in a 74-page manifesto. The arguments and motivations laid out in the document need to be taken seriously and not merely dismissed as the ravings of a fanatic. That’s the only way to reckon with the gravity of what happened and to confront a threat that will be with us for decades to come.

It is reasonable that we would want to cast such an attack outside the realm of rationality, to tell ourselves that expressions of evil are random and unpredictable; it’s the same impulse many had when faced with the brutality and terror of the Islamic State and other jihadi extremists. To rationalize evil as something irrational makes it easier to take on horrifying news. But to do that here would be a mistake.

I won’t link to the accused shooter’s manifesto. But I think it’s important for analysts and government officials to read it carefully. This is what many of us did when the Islamic State would release its recordings and statements.