Paradoxes are arguments that lead from apparently true premises, via apparently uncontroversial reasoning, to a false or even contradictory conclusion. Paradoxes threaten our basic understanding of central concepts such as space, time, motion, infinity, truth, knowledge, and belief. The care and feeding of your new paradoxes -- The truth about truth -- The title of this chapter will have its revenge -- Some collections are bigger and badder than others -- Bald, not bald, and kinda bald -- What we know about what we know -- Conclusion: many paradoxes, one solution?