From the Chuang-tzu

Many are those under heaven who attend to their theories and techniques, and they all believe that nothing can be added to the ones they possess... How sad that the hundred schools go along their own ways without coming back so that they will of necessity never join together! The students of later generations have unfortunately not seen the simplicity of heaven and earth. The techniques of the Way as they were so greatly embodied by the men of antiquity are being sundered by all under heaven...

--Chuang-tzu Chapter 33, trans. V.H. Mair