reason (cause) / reason (mental faculties) / common difference (of an arithmetic series) / common ratio (of a geometric series)

raison d'être

(politics) a state interest, especially when invoked as politically superior to moral or even legal considerations

(of a person) to be right; to be correct

(transitive with à) to prove someone/something right, to bear someone/something out / (transitive with à) to agree with

to see sense, to see reason, to listen to reason

with good reason, rightly, understandably

(literary) to be reasonable

(transitive with de) to account for, to explain; to justify

to get the better of (someone) / to overcome (something)