There comes a point where, if your arguments are true, they disprove your position as thoroughly as if they weren’t. For instance, you sometimes hear socialists claiming that ‘real’ socialism has never been implemented, meaning that the track record of Marxist politics shouldn’t be taken as an indictment of the idea itself. But if that’s true, and if socialism is so difficult to implement that a century’s worth of attempts all over the world have universally failed to the tune of tens of millions of lives, that itself would make it a terrible idea.