The four siddha^ntas. Four modes whereby the Buddha preached the originally inexpressible dharma to all sentient beings. They are as follows: （1） shijiexitan 世界悉檀 Worldly siddha^nta. Preaching which accords to the conventional understanding of the world. （2） gegeweirenxitan 各各为人悉檀 Siddha^nta for each individual. Preaching according to the abilities and levels of understanding of the people listening. （3） duizhixitan 对治悉檀 Special application siddha^nta. Preaching aimed at destroying strong defilement or evil karma of certain beings. （4） diyiyixitan 第一义悉檀 Siddha^nta of supreme truth. Preaching of reality as understood by the Buddha himself.