Paradoxes of this kind have been known since antiquity (the standard Liar is attributed to the Greek philosopher Eubulides, probably the greatest paradox-producer of antiquity). But they were thrown into prominence by developments in the foundations of mathematics around the turn of the twentieth century. In the case of each paradox, there appears to be a perfectly sound argument ending in a contradiction. If the arguments are sound, then dialetheism is true. Of course, many have argued that the