首楞嚴義疏注經 8.542

8.542

因由訟習，鬼作依人，傳附神辭，發顯禍福，畜招馴黠。人達窮通，寵辱不驚，安然自得，故名達類。

Their cause was from the habit of litigation: as ghosts they acted as possessing spirits, conveying and attaching divine utterances to reveal misfortune and fortune; as animals they incurred docility and craftiness. As humans they discern adversity and prosperity, remain unfazed by favor or disgrace, and are tranquil and self-possessed; hence they are named the discerning category.