reason

A cause:

Rational thinking (or the capacity for it); the cognitive faculties, collectively, of conception, judgment, deduction and intuition.

“Mankind should develop reason above all other virtues.”

Something reasonable, in accordance with thought; justice.

Ratio; proportion.

To deduce or come to a conclusion by being rational

To perform a process of deduction or of induction, in order to convince or to confute; to argue.

To converse; to compare opinions.

To arrange and present the reasons for or against; to examine or discuss by arguments; to debate or discuss.

“I reasoned the matter with my friend.”

To support with reasons, as a request.

To persuade by reasoning or argument.

“to reason one into a belief; to reason one out of his plan”

(with down) To overcome or conquer by adducing reasons.

“to reason down a passion”

(usually with out) To find by logical process; to explain or justify by reason or argument.

“to reason out the causes of the librations of the moon”