“Okay, so what is the speed of dark?” Someone has said that a good one-liner is just as much an art form as an epic poem. Apart from whether or not this claim can be justified, Steven Wright, the gloomy-eyed comic whose humor is as surrealistic as Dali’s paintings, is, indeed, an artist.

Despite a deadpan delivery, his humor tickles the funny bone and teases the mind. And his humor invites people to imagine what it might be like living outside the borders of reality. For example, he tells of how he went to eat at a restaurant that advertised “breakfast at any time.” So he ordered French toast during the Renaissance.

Well, if we can measure the speed of light, why can we not measure the speed of dark? Turning to Paul the Apostle, we are told that light and darkness have nothing in common (2 Corinthians 6:14). And if they have nothing in common, they have no basis for both being measured. The speed of light is measurable; the dark has neither speed nor being.

This distinction is by no means frivolous since, throughout history, light and dark have been associated with good and evil. If darkness, then, is something real, so is evil. The theological question that follows is whether God can be the author of evil.

Manichaeism, a philosophy that thrived between the third and seventh centuries, taught a dualistic cosmology in which human life is seen as a struggle between two antithetic forces: a spiritual world of light and an evil, material world of darkness. In this way, being was ascribed to darkness.

St. Augustine was an adherent of Manichaeism for nine years and held that light and darkness, just as good and evil, were both positive. This would mean that one God could create evil, just as another God could create good. Augustine came to see, however, that evil has no being of its own and is a privation of something that is good. Therefore, evil is not something that could be created. It is parasitic, dependent on the existence of something that is good. An apple can be corrupted, but the corruption cannot exist by itself; it needs the apple in which to inhere.

Through considerable struggle and soul-searching, Augustine came to the following conclusion:

“For the Almighty God, who, as even the heathen acknowledge, has supreme power over all things, being Himself supremely good, would never permit the existence of anything evil among His works, if He were not so omnipotent and good that He can bring good even out of evil. For what is that which we call evil but the absence of good?”

Consequently, nothing can be called evil insofar as it has being, but only insofar as it is deprived of being.

In his work Disputed Questions on Evil, St. Thomas Aquinas states,

“Evil is not a positive thing, but that in which evil adheres is something positive, insofar as evil takes away only a part of the good. In the same way, blindness is not anything positive, but he who happens to be blind is something positive.”

In Genesis, we read that “darkness was upon the face of the deep.” But this “darkness” was not something positive, but a formlessness. When God said, “Let there be light,” he endowed creation with something positive by making it both visible and understandable, appealing to the eye as well as to the mind.

Manichaeism is not entirely dead in our own generation. Neither light nor dark, good nor evil have anything in common. Nonetheless, the notion persists that evil is not a deprivation of good, but a positive choice.

Some people live in a kind of twilight zone in which light and dark, good and evil each have their own values. In this way, they can claim to be “open-minded.” St. Paul reminds us that “the spiritual man judges all things, but he himself is not subject to anyone’s judgment” (1 Corinthians 2:15).

What he is saying is in accord with Proverbs 28:5: “Evil men do not understand justice, but those who seek the Lord comprehend fully.” This is to say that those who have the light of truth cannot be judged by those who lack this light. Good can judge evil, but evil cannot judge good.

Debates are futile in which one participant is enlightened while the other is in the dark. Being in the dark is a deprivation that renders a good moral judgment impossible. Those who understand that killing innocent people is evil cannot be judged by those who hold the opposite view. Evil cannot judge the good no more than darkness can judge light.

Good and evil are not contraries, like male and female, hot and cold. They do not belong to a common genus. Evil is the privation of something good and has no independent existence.

People who cling to an evil position are not inclined to accept that their position is essentially defective. They want others to believe that a diversity of opinion in a pluralistic world is perfectly legitimate. Therefore, it is difficult for some people to see the light, that Veritatis Splendor (Splendor of Truth) that St. John Paul II called it.

No one tries to measure the speed of dark because dark has no speed. Yet people do attempt to substantiate an evil position. One reason for this is that a single and solitary defect can make something bad, while goodness requires wholeness. It takes less effort, therefore, to be wrong than to be right. Taking this imbalance into consideration, St. Paul offers us some sound advice:

“Brothers and sisters, if someone is caught in a sin, you who live by the Spirit should restore that person gently. But watch yourselves, or you also may be tempted” (Galatians 6:1).

The enlightened must also be humble, vigilant and circumspect.

Donald DeMarco, Ph.D., is a senior fellow with Human Life International and is the author of Why I Am Pro-life and Not Politically Correct.