When a person makes a choice, he does so as the result of a judgment he has made about whatever information his intellect has been fed. If he makes a judgment with a minimum of information, it will basically be an un-informed judgment and his choice will reflect that.
Our free will need not be left to chance. Ordinarily, we ought to make judgments that are as informed as possible so that our choices will be intelligent and reasonable.
The choice as to whether we will act with reason or not is ours. This is what we mean by “free” will. To choose to sin is not a reasonable choice (although it may seem so at the time) because it is ultimately self-destructive.
Fr. Vincent Serpa, O.P.