Anders Behring Breivik
Is Anders Behring Breivik insane? In a clinical sense, no. Yet, from another perspective, no one (in their right mind that is) could possibly confuse Breivik with being sanus — sound, healthy.
“Blinded by hate” is not just a figure of speech. Hate makes insane. An all-consuming hate casts a thick fog over the senses, until one perceives nothing clearly through the pall it casts over everything, even oneself. Truth and falsehood become irrelevant because no longer accessible. Everything becomes subordinated to a dualism of love and hate.
In that sense, Breivik is demonic and willingly embraced the demonic. But it is a convention of the wisdom tradition that to become demonic in that way is to enter into insanity and into the lowest circles of Hell.