アキレスと亀：なぜ追いつく必要がないのか

－野矢・青山・植村論文の検討－

抄録

    Achilles need not catch the tortoise, although Achilles is faster than the tortoise. Zeno's premise does not determine whether Achilles can catch up. In this paper, I clarify this fact through a critical examination of Noya (2005), which criticizes Aoyama (2002) and Uemura (2002). Noya's solution smuggles the unnecessary premise of equal ratio to make Achilles catch up. However, his solution gives a new idea about what speed is. In the last part of this paper, I develop this idea and explain the reason why Achilles usually catches up in the actual world.