Augustine explained providence as a natural grace that God gives freely to all human beings. It is some unexpected external act that causes a person to stop and think, and possibly to choose a better course.
An act of providence can arise from a fortunate event, or an unfortunate one. It could be caused by pleasant surprise, or by a setback. It could be the birth of a child, or (as in the case of Augustine) the death in quick succession of persons close to the heart. External providence can stimulate a re-examination of motives. It can be positive thinking which leads to a conversion of heart and to any necessary change in behaviour.
Augustine distinguishes very explicitly two orders of grace. Only the first of the two is relevant here. The first is a natural grace of natural virtue. It that includes the simple gift of Providence. This prepares efficacious motives for the will. In the writings of Augustine, examples of providence are most notable in his City of God and Confessions. He incorporated providence into his world view in which he saw all creation as a narrative that progressively revealed the plan of God for creation.
Even though God gave free will to human beings, God has an absolute plan that human beings can delay but are unable to stop. The same plan appears in Paradise Lost by the English poet, John Milton (1608 – 1674). Like Augustine, he wrote to justify the ways of God to humanity. Augustine had recourse to explain providence when balancing his theological thoughts about grace (in Latin, gratia), evil and predestination.
Providence in the Confessions of Augustine. This is a talk by Brian Lowery O.S.A. of Convento Sant’Agostino in San Gimignano, Tuscany, Italy. For a PDF file, click here. Christus medicus. Latin words for "Christ the doctor." Augustine once referred to the Church as "a hospital for sinners," and Christ was its doctor. The following PDF presentation is by the late Augustinian scholar, Fr Thomas Martin OSA. http://www.augustinianfriends.com/readingroom/Christus_Medicus.pdf