On the contrary, it's a tautology. There are only a finite number of articles, so either your chain reaches philosophy, it ends because there are no links/broke

On the contrary, it's a tautology. There are only a finite number of articles, so either your chain reaches philosophy, it ends because there are no links/broken links, or it gets stuck in a loop. The other possibility is that it never ends but never reaches philosophy, but that means it must loop since there are only finite number of articles. The interesting thing is two fold: most articles end up in the philosophy case, and the loops that do exist tend to be small.