Final answer:
St. Augustine formulated the doctrine of Original Sin, according to which all of humanity participated in the sin of Adam and Eve and suffers its consequences. He believed that it is within our power to choose the good despite the original sin.
Step-by-step explanation:
The doctrine of Original Sin, according to which all of humanity participated in the sin of Adam and Eve and suffers its consequences, was formulated by St. Augustine. Augustine proposed that humankind is responsible for evil due to the Fall of humanity after the disobedience in the Garden of Eden. He believed that it is within our power to choose the good despite the original sin. Divine grace is necessary to ultimately resolve the conflict between good and sinfulness.