梯子的功用是登高,或者说向上爬。这在一般人的心目中,是毫无疑义的。然而如果细想一下,其功用还可有另一面:从高处往下降。这一点,恐怕就不是人人都会去想的了。此说虽出常人意料,但仔细想起来,却完全符合辩证法。上与下,升与降,本来是一对对立的矛盾,但矛盾的双方又是互相依 The function of a ladder is to ascend, or to climb. This is beyond doubt to most people’s minds. However, if you think about it, its function can also have the other side: descending from a height. This point, I am afraid not everyone will think about it. Although this is an ordinary person’s surprise, it is fully in line with dialectics. Up and down, up and down, originally a contradiction between the contradictions, but the contradictory sides are interdependent