Jacob Northrop can quantitatively prove that human society has been turning away from its search for truth. He's got numbers. He's got graphs. And they clearly show that, after a peak somewhere in the late twentieth century, the tendency of human civilization to rigorously seek truth has faded. We have given up fighting the urge to lie to ourselves, to accept comforting half-truths, to listen to leaders who tell us what we want to hear, and all the other logical fallacies and epistemic vices. We gave up the courage to turn toward truth.
And Jacob believes there's Lethetropine in the water. He believes the government, or "them," or the Illuminati, or somebody, has been feeding something to humanity to make them believe what they're told. To make them more credulous. To make them stop questioning. And it is destroying the human race.
And he can't get anyone to believe him. And there are supporters. And there are deniers. And the powers that be try to shut him up (which gives his believers a shot in the arm). And of course the people supporting him are no less credulous than their opponents. He might as well be just another charlatan.
And he dies alone and mad.
And wrong.
Because there never was any Lethetropine. There was no grand conspiracy. Oh, there were conspiracies, sure, but not competent ones. And none that were responsible for the decline of human civilization.
It's just human nature to believe.