Here is the tell that a belief has stopped being a theory and become a faith. Nothing can count against it.
The twentieth century handed the doctrine of progress the worst run of evidence any idea has ever been asked to absorb. Two world wars. Seventy to eighty-five million dead in the second one, around three per cent of everybody alive. Industrialised extermination with paperwork and timetables. The Gulag.
And the doctrine survived intact. Every one of those was absorbed as a setback. A dip. A deviation from the trend line, which remains, we are assured, upward.
Run that move past yourself slowly. A claim that can absorb the Holocaust as a rounding error is not being tested by evidence. It is being protected from it.
Progress is not a political position. It is a complete worldview that answers exactly the questions religion answers, and declines to admit that is what it is doing.
It has a creation story: we came out of darkness, superstition and savagery, and climbed by reason toward the light. It has scripture, in the Enlightenment canon. It has an eschatology, and it has got noticeably more explicit lately: artificial general intelligence, other planets, the abolition of death.
And it has heretics. This is the part that gives it away. Suggest that the line does not always go up, or that material progress and moral progress might be two different quantities that can move in opposite directions, and you do not get counter-evidence.
Francis Fukuyama argued that ideological history was finished.
The Western intelligentsia loved it, because it said the thing they wanted said: that their arrangement was not one option but the destination.
What most of them skipped is that Fukuyama told them it would be awful. In his own words, the end of history would be "a very sad time". No causes worth dying for. Life reduced to economic calculation, technical problem-solving and the satisfaction of sophisticated consumer demands.
He was not only predicting the victory. He was predicting that the victory would be hollow, and on that half he has been vindicated more thoroughly than on the other.
I am not arguing that nothing has improved. Child mortality has collapsed. Anaesthesia exists. These are not small and I am not interested in the pose that pretends otherwise.
A theory that cannot lose has stopped doing the work theories do. It is no longer telling you about the world. It is telling you where you sit in a story, and the story has you at the top of it, which is precisely why it is so hard to give up.
Ask the question the doctrine cannot survive. Not are we richer, which is settled. Ask whether we are better. Ask what we would be willing to lose something for. Then notice how quickly the conversation is redirected back to the graph.