The legions of protesters and rioters filling TV screens don’t much care about the underpinnings of the campaign for justice, so-called, but they should. The organizers of Black Lives Matter (BLM) clearly care, and it is the philosophy that animates the movement and is steering it toward a dangerous place most Americans would flee if they understood what awaits them.

In comments uncovered and reprinted in The National Pulse, Black Lives Matter co-founder Patrisse Cullors reveals that she and fellow co-founder Alicia Garza are followers of an ideology that could not be more foreign to the American way: “We actually do have an ideological frame. Myself and Alicia in particular, we’re trained organizers. We are trained Marxists. We are super-versed on ideological theories.”

Ms. Cullors is unapologetic in describing Black Lives Matter founders as “trained Marxists,” so it’s worth examining the words that inspire their deeds. Marxism, the 19th-century worldview systematized by German revolutionary Karl Marx, is fundamentally atheistic. It subscribes to a theory that matter — physical stuff — comprises the fundamental reality of human existence. The transcendent experiences of the human heart are regarded as nothing more than biochemistry — fantasies of brain function. Stuff, whether molecule or man, is just soulless stuff. In short, matter doesn’t really matter.

Students of history have seen it all before. The Marxist revolutions of the 20th century that wracked Russia, China, Vietnam, North Korea and elsewhere piled up victims approaching 100 million. Thus is the bitter harvest of the perpetually angry, steeped in Marxism and deaf to the call for human kindness.

It is easy to stir up an argument over whether the NFL’s Tom Brady chose wisely in becoming a Buccaneer rather than remain a Patriot, but there is no counterargument to the proposition that black lives matter. As they wholeheartedly endorse the intrinsic value of the black race, though, Americans are tiptoeing around the controversy posed by an organization that shrewdly shields itself from scrutiny behind the BLM brand.