符瑞、災異是天命思想中的兩個組成要件。符瑞的作用在證明政權的合法性，災異的作用在約束君或臣的濫權。三國時代符瑞、災異思想頗為盛行，當時對於符瑞的運用，有下列四種方式：一、用以合法化新政權的建立。二、用以合法化繼承帝位。三、用以合法化政權的永恆性。四、用以合法化對政權的篡奪。對於災異的處置與運用，則有下列三種方式：一、君主因災異詔責己或責臣。二、臣藉災異上疏諫君或責臣。三、君主利用災異迫害臣。 Fu Rui,the auspicious signs,and Zai Yi,the abnormity of disasters,are the two fundamental institutions of the legitimacy of succession to the throne.The function of Fu Rui is to prove the legitimacy of political power,while the function of Zai Yi is to retrain the monarch and official excessive power.During the Three Kingdoms,Fu Rui and Zai Yi were very popular.At that time,for the application of Fu Rui,there were four forms:(1)to prove the legitimacy of the establishment of the new regime;(2)to prove the legitimacy of succession to the throne;(3)to prove the legitimacy of the immutability of political power;(4)to prove the legitimacy of the struggle for political power.As for the treatment and application of Zai Yi,there were three ways:(1)The monarch blamed himself or his officials because of Zai Yi.(2)The official wrote a letter to persuade the monarch or blamed other officials.(3)The monarch persecutes the officials on the excuse of Zai Yi.
