How do we determine the goodness or badness of an act? For instance, what makes murder evil and almsgiving good? Simply, acts are good if they perfect human beings. They make us the persons we were made to be by fulfilling those needs that we have by virtue of our common human nature. Bad acts, on the other hand, detract us from our proper end. They make us less than the persons we were made to be.
To illustrate this, consider a pencil. What is a good pencil? A good pencil is a pencil that writes well. Thus, a good pencil needs a sharp tip. Consequently, sharpening a pencil is good for the pencil because having a sharp tip allows it to be used to accomplish its purpose. In contrast, breaking the lead of the pencil is bad for the pencil because a pencil without a tip cannot be used to write. It cannot be used for its proper end. In an analogous way, good acts are those freely chosen acts that perfect us. They fulfill those needs that we have by virtue of the fact that we are human beings, thus making us the type of persons that we were made to be.
Reflecting upon the nature of creation, St. Thomas Aquinas, the great medieval Dominican theologian and Doctor of the Church proposed that there are four basic needs intrinsic to human beings: to live, to procreate, to live in community, and to know the truth especially about God and about ourselves. These needs are inter-related and mutually support each other. First, we need life to strive for our goals and for our perfection. This is the most basic need necessary to achieve all our other needs. Next, we need to procreate to preserve the human community that we need because we are social creatures who can only attain our perfection in communion with others. Finally, we need to know truth because it is truth that gives our lives meaning and purpose. Ultimately, of course, we need to know the truth about God in order to attain the happiness that is friendship with him.
Human acts that are in conformity with the four basic human needs are good. They are good for the person. They express the rational order of good and evil impressed into the very nature of creation. In contrast, there are acts that are not in conformity with this order. These acts are evil because their objects are “by their very nature incapable of being ordered to God because they radically contradict the good of the person made in his image” (Veritatis splendor, no. 80). In other words, these acts are evil because they do not promote the perfection of the individual human being who is the image of God, the imago Dei. Thus, the Cathecism teaches that “there are acts which, in and of themselves, independently of circumstances and intentions, are always gravely illicit by reason of their object; such as blasphemy and perjury, murder and adultery” (CCC, no. 1756).
(© 2011 Fr. Nicanor Pier Giorgio Austiaco, O.P.)