I’m going offline for a few days, so here’s a thought experiment that I copied and pasted; "A certain barber is very particular about his work. He shaves every person who does not shave themselves, and no one who does shave themselves. So: does the barber shave himself? It doesn't take long to see the contradiction: If he does, he can't; if he doeesn't, he must. Such a barber can't exist."