We manage to discover some regularities in the flux of existence and to cope with our environment ,only because we treat different things as equivalent by categorizing our experience .

• 我们之所以能够在不断变化的现实存在中发现某些规律，并且得以应付我们的环境，只是由于我们通过将自己的经验分类而把不同的事物等同起来。