《淮南子·泰族训》
如果持守一角就会抛弃遗漏万方世界，如果取用一物就会舍弃其他事物，这样就必定获得的很少，所能治理的范围也一定很浅窄。
夫守一隅而遗万方，取一物而弃其余，则得者者鲜，而所治者浅矣。
If one sticks to one corner, one will abandon the vast world; if one takes one thing, one will give up other things, so one will definitely gain very little and the scope that one can manage will definitely be very narrow.