Answer:
1. Saint Augustine tried to reconcile these two ideas by stating that there are conditions for the two states. He said that necessity requires God's foreknowledge while freedom required man's will power. These are two independent sources that do not affect the other.
2. I do not think that he succeeded.
Step-by-step explanation:
There was a basic understanding from Saint Evodius which Saint Augustine denied. It was that; since God had foreknowledge that man would sin, he would necessarily or inevitably sin. Thus if a man should necessarily sin, then his sin was not voluntary. Saint Augustine's explanation for this was that the two personalities involved, that is God and man had different conditions to display their strengths. While inevitability required God's ability to know the future, man's freedom comes from his own power to choose.
Saint Augustine's reasoning sounds vague to me. I would rather opine that even though God has the power to know the future, he does not necessarily always exercise that ability. Just as a boxer would not go about exercising his strength on everyone he sees, so God not does use his foreknowledge at all times. This allows man the ability to exercise his freedom and free will. Moreover, it is inevitable that man would sin due to his imperfect nature, but the presence of the conscience makes him chose whether to or not to sin