The pitfalls of a pseudo-mathematical method, which can make no progress except by making everything a function of a single variable and assuming that all the partial differentials vanish, could not be better illustrated.

伪数学方法的缺陷无法得到更好的说明，除非将所有事物都作为单个变量的函数并假设所有偏微分都消失，否则它不会取得任何进展。