sanity
/ˈsænətɪ/noun
mass noun
1- the ability to think and behave in a normal and rational manner; sound mental health精神健全, 精神正常：
I began to doubt my own sanity.
我开始怀疑自己精神是否正常。
1.1
- reasonable and rational behaviour明智; 清醒; 通情达理。
词源
late Middle English （in the sense 'health'）： from Latin sanitas 'health', from sanus 'healthy'. Current senses date from the early 17th cent.