永远不要把一次失败和最终的失败混为一谈。
真相很少纯粹,也绝不简单。
教育学中的实验方法不仅是研究的工具,更是理解教育过程的基本原则。
The deterioration of every government begins with the decay of the principles on which it was founded.
The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.