الْعَقْلُ
The faculty through which meanings, judgments, and conclusions are grasped.
Reason should not be restricted to constructing long formal proofs. Some meanings and elementary judgments are immediately intelligible, whereas other results arise through connecting premises. Reason may also draw conclusions from material supplied by the senses, so the intellectual step can be distinguished from the earlier observation.
If every square has four sides and the drawn figure is a square, its having four sides follows by reasoning from the premises. The result is not merely a visual sensation nor merely someone's report; the operative step is apprehending the relevant connection.