he.don.ics
n.(used with a sing. verb)（名词）（与单数动词连用）The branch of psychology that studies pleasant and unpleasant sensations and states of mind.快感学：心理学的一个分支，研究快乐和不快乐的感觉及大脑状态Philosophy The branch of ethics that deals with the relation of pleasure to duty.【哲学】 快乐说：伦理学分支，研究快乐和义务的关系
