Saint Thomas Aquinas, in his great Summa Theologica, begins his treatment of ethics with the Christian understanding that human beings are created in the image of God. Following Saint John Damascene, he observes that human beings image God most especially through having intelligence and free will. Saint Thomas teaches that the human beings image God in three ways: (1) by their natural aptitude for knowing and loving God, (2) by their actual knowledge and love of God through the gift of God’s grace, and (3) by their perfect knowledge and love of God in the Glory of eternal blessedness. In the first way, the image of God is found in each and every human being. In the second and third ways, the image of God in human beings can be distorted or even lost. In every human being, God’s image has been distorted by original sin and, in nearly every human being past the age of reason, by the misuse of human intelligence and freedom that constitutes personal sin. But the image of God can be restored in human beings by God’s grace and through their free cooperation with that grace. And just as the distortion of God’s image is brought about through the bad use of human intelligence and freedom, the restoration of God’s image is effected through their good use.

Saint Thomas uses the term “human acts” to denote the free and intelligent actions of human beings. Human acts are actions that are characteristic of human beings who are made in the image of God. A human act is something that a human being does deliberately and intentionally. Human acts can be good or evil. When human acts are evil, they distort the image of God in the human beings who are responsible for that evil. When human actions are good and in cooperation with God’s grace, God’s image is restored in the human beings who do good.

Being restored in God’s image, therefore, has to do with the quality of human acts. Deciding to act in good ways and not in bad ways is important, not only because the actions of one person have an affect on others, but also because they have an effect on the person who performs those actions and on his relationship with God. It is by good human acts that human beings contribute to the formation of their character, determine what sort of persons they are to be, and decide whether God’s image in them will be distorted or restored.

Restoring God’s image depends on God’s grace and, for those capable of acting freely, involves the performance of good human acts. A good human act expresses and confirms the character of a good human being. A good human act pursues the good things that God has created the human heart to desire: things like knowledge of truth, the preservation and flourishing of life, and just and peaceful society. A good human act is performed when a human will is directed by right reason to accomplish truly good purposes by the use of truly good means. A good human act contributes to the making and remaking of God’s image in the human being that performs it.

On the contrary, a bad human act expresses and confirms the character of a bad human being, pursues disordered purposes or good purposes by disordered means, proceeds from a corrupted will, and contributes to its further corruption. A bad human act is a sin and contributes to the corruption of the image of God in which all human beings were made.

Ethics is the study of the goodness and badness of human acts. For Saint Thomas Aquinas and the Catholic tradition he represents, this means that ethics is most profoundly about the dignity of the human person created in the image of God. Human dignity is promoted when human beings, aided by God grace, choose to perform good human acts. Human dignity is violated, and God’s image in human beings is distorted, when they willingly act in ways that bad.

When we apply what we have said about ethics in general to the consideration of medical ethics in particular, we can conclude that medical ethics is most profoundly about how human dignity is either promoted or violated, and how God’s image in human beings is either restored or distorted, through the human acts that have to do with medical practice. Do the actions of doctors, nurses, researchers, patients, and patient representatives pursue the authentic goods that God has created our hearts to desire? Do health care professionals fix their wills only upon what is good and refuse to do what is bad for the sake of achieving their desired goals? How do the actions of health care decision makers make us more or less human and so contribute to the distortion or restoration of the image of God in which we were made?

Beginning to answer these questions requires that we think of our medical acts as human acts and our medical decisions as choices that determine what kind of human beings we are to become. Our human acts have profound importance for others and for ourselves. Let us act in such a way that, through the gift of His grace, the image of God may be restored and perfected in us.