The multiplicity of Pre-Socratic theories concerning the nature of the world had become embarrassing by the middle of the fifth century BC, and many reasonable men began to despair of finding a way of settling the questions they dealt with.

• 到公元前5世纪中叶，苏格拉底之前的人们对世界本质的看法实在太多了，以致让人不知所从，许多明智之士开始对如何解决这些问题感到绝望。