The Author starts the book by answering the question: "What is the greatest gift of God" and, next, presents the panorama of 2000 years of study on free will, asking if we really are free, or if we make our choices by strength of internal and external influences.The approach chosen by the Author is based on the Sacred Scriptures and the logic of thought, discussing the various schools that dealt with human freedom, from Pelagius of Brittany to John Calvin.