道理 (どうり, douri) Japanese meaning: reason | Kotomora。
What he says is reasonable.
Usage patterns
道理を説くto explain the reasoning or moral principle behind something
The teacher explained the moral reasoning to the children.
道理をわきまえるto understand right from wrong; to be sensible
He is a person who understands right from wrong.
〈事〉は道理だit stands to reason that...
It stands to reason that effort leads to success.
Expressions
道理に外れたcontrary to reason; unreasonable; irrational