2) Augustine's view of the Fall saw mankind as a massa peccati, a "mess of sin," incapable of raising itself from spiritual death. It was the doctrine of total depravity. "No one is good, not even one." According to the Scriptures, man is so fallen, so darkened in his heart, mind, and will by sin, that he is unable to turn from sin and embrace the truth of the Gospel and obey God's commandments. For Augustine man can no more move or incline himself to God than an empty glass can fill itself. For Augustine the initial work of divine grace by which the soul is liberated from the bondage of sin is sovereign and operative. To be sure we cooperate with this grace, but only after the initial divine work of liberation. He believed sin originated with free will which implied the ability to do evil. (3-4) Aquinas conceives of creatures, according to types, as governed by final causes or ends which they naturally seek. These ends are implanted in them by the Creator. Most creatures actively seek their proper ends out of instinct. Although human beings too have proper ends, we do not always act as we should. Our actions are often determined counter to nature and natural law by our appetites. When reason rules in the human soul, we choose what accords with nature.
Reason in human beings is capable of apprehending certain general principles implanted in human nature. The first principle of the natural law is "good is to be done and pursued, and evil avoided" (q94, a2, p. 47). All other precepts of natural law rest upon this. What Aquinas seems to mean is that the several precepts of natural law are specifications of this precept, which is highly abstract). These other precepts include (p. 48):
Whatever is a means of preserving human life and of warding off its obstacles