perfectly reasonable; standing to reason
Emphasizes that something is entirely consistent with reason or logic; often used in formal or emphatic contexts.
His argument is perfectly reasonable.
They made a decision that stands to reason.
至極当然 also means 'perfectly natural' or 'quite reasonable', but it is more common and less formal than 道理至極.
理にかなう is a verb phrase meaning 'to be reasonable' or 'to make sense', used in everyday speech, while 道理至極 is a more emphatic, formal noun/adjective.
Compound of 道理 (reason, logic) and 至極 (extremely, most). The exact historical derivation is uncertain, but the combination yields the meaning 'extremely reasonable' or 'perfectly consistent with reason'.