Counterfactuals, the buzzy term being touted in the latest AI news, assert some impressive promises for the tech world. But the general idea is nothing new. Counterfactual thinking describes the human drive to conjure up alternative outcomes based on different choices that might be made along the way—essentially it’s a way of looking at cause and effect. Counterfactual philosophy dates back to Aristotle, and along the way it’s been debated by historians and even written about by Winston Churchill in his 1931 essay, “If Lee Had NOT Won the Battle of Gettysburg.” In more recent years, scientists have found that it’s possible to translate such counterfactual theories into complex math equations and plug them into AI models. These programs aim to use causal reasoning to pour over mountains of data and form predictions (and explain their logic) on things like drug performance, disease assessment, financial simulations and more.