The laws of thought are the foundation of all exact reasoning.
思维法则是所有精确推理的基础。
正该来时,先生(老子)应时来到这世间;正该去时,先生顺时离开这世间。安于时势,顺应自然规律,哀乐就不能进入心中。
经济学的研究最终是对人类行为及其后果的研究。
"The aim of life is self-development. To realize one's nature perfectly—that is what each of us is here for."