Reason adapts impulses and beliefs into the real world; rationalization, on the other hand, adapts the concept of reality to the impulses and beliefs of the individual. Reasoning discovers the true cause of our acts, rationalization finds good reasons for justifying our acts.
Gordon AllportGiven a thimbleful of [dramatic] facts we rush to make generalizations as large as a tub.
Gordon AllportPersonality is and does something...It is what lies behind specific acts and within the individual
Gordon Allport