What is the difference in the usage of 理由 vs 原因? Both seem to translate to "reason."
According to my understanding, 理由 is more like the rationale behind a decision, behind a move, etc. and 原因 is more like the reason for coming late, the reason for doing something? Any clarifications or suggestions?
理由 (logic + cause): justification; argument; reason
原因 (origin + cause): cause; reason
When stating a 理由 (reason) for an action, you need to explain the justification, logical argument for the action
When stating a 原因 (reason) of an action, you need to state the origin or cause of the action
Example:
秦儈殺岳飛的理由是'莫需有'
The reasons (justification) for Qin Yu to kill Yue Fei was 'no need to state'
He didn't have any justification so he just said it is not necessary to have one
~
秦儈殺岳飛的原因是為了迎合高宗
The reason (cause) of Qin Yu killing Yue Fei was he wanted to cater to the Emperor (Gao Zong).
Gao Zong's father and brother were the two previous two Emperors who were captured by the enemy. Yue Fei wanted to defeat the enemy was a good thing, but he also wanted to save the two former Emperors and bring them back home. Gao Zong cannot openly object that, but everyone knew having the former Emperors back would endanger Gao Zong's status as the Emperor. Qin Yu wanted to please Gao Zong was the cause of his action
Simpler examples:
開除他的理由 The justification (reason) for him to be fired
開除他的原因 The cause (reason) of he being fired
原因 is a condition that causes an outcome or another event, such as an accident.
But is also have some means of reason.
ex: We do not yet know all the 原因(causes) of blindness.
理由 is the reason why something is done this way or that way
ex:
A: Primary and secondary schools should fully implement the teaching of mother tongue.
B: why? Please give three 理由(reasons).
借口 is another similar word and it has a certain emotional color, like excuse.
ex: Don't make 借口(excuses) for your being late.
原因 and 理由 are often mixed in daily communication.
answered by online dictionaries, e.g. (excerpts from) bkrs: 理由：［reason grounds justification CL:个] 事情的道理、 根由 事情的道理 e.g. 理由不足的答辩,没有理由抱怨,有充分理由相信,他没理由抱怨你 #1636
原因 cause origin root cause reason 1) 由于某原由而产生 2) 事态的起因 e.g. 原因和结果 成功的原因 由于这个原因 将其归之于心理上的原因 原因在于 这次冲突有着非同寻常的原因 真正的原因在于他事事要随心所欲 #577 同义: 缘故, 原故, 原委, 原由 (for English see bkrs, dictionaries show 原因 independent of human thought/argumentation,which are implied by 理由)
