Cassian (360-435 A.D.) was abbot of the monastery of Massilia. He opposed both Pelagius's and Augustine's doctrines and proposed a middle way. Semi-Pelagianism is often named Cassianism because its distinctive approach to grace originated with the abbot. Cassian sought to preserve the universality of grace and the real moral accountability of fallen man. It was the issue of Augustine's irresistible grace to which he vigorously reacted. For Cassian, man's free will was impaired by the Fall of Adam. It became infirm or sick. But it was not dead or inoperative. It could respond on its own to the Gospel. When God sees a sinner using his will to the good, He immediately moves to assist that will by way of illumination, comfort and incitement toward salvation. The key point is the initial striving of good will in the sinner. In Augustine's scheme, the will is disabled and incapable of making any initial striving toward God. It requires initial grace. Cassian affirms that the will, though impaired, is still able to initiate. Possessing an ability in his will to cooperate with divine grace, man is capable of moral renovation assisted by grace. In later Medieval theology the term "facere quod in se est" = "Do whatever is in you" The implication of this is that if that sinner does what is in him, then God will do the rest and bring him to salvation.