Justice Potter Stewart observed in Jacobellis v. Ohio (1964) that while hard-core pornography is difficult to define, “I know it when I see it.” The same is true of evil.

A decent conscience, uncontaminated by ideology, knows what it is looking at. The torments that Hamas “militants” inflicted on Oct. 7—mass slaughter, rape, the beheading and incineration of babies—amounted to behavior that the high court of any uncorrupted intelligence in the world would describe as evil.

What other word would be sufficient? Wicked? Gruesome? Atrocious? Naughty? No one with any brains uses the word evil lightly. I tend to capitalize it to give the concept (vile, mysterious, theologically absolute) its metaphysical due. President Biden chose his language carefully when he spoke of the Hamas raids as “pure, unadulterated evil.” Since Oct. 7, the word—from which people used to shy away, regarding it as radioactive, over-the-top—has become commonplace and almost unavoidable.