Meaning of active reason

ac'tive rea'son

Pronunciation: [key]
— Aristotelianism. Aristotelianism.
  1. an activity of intellect, embodying universal truth, potentially present in the mind of every individual, and when present, forming the only immortal part of the individual. Cf. passive reason.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.