This is the second-to-last post summarizing the position on killing laid out by Thomas Aquinas in the Summa. In the concluding post I will pull together a number of points about his position on killing. In this post I will discuss the last question in the Summa’s article on killing: “Whether one is guilty of murder through killing someone by chance?”

As in other questions (e.g., article 6 on whether it’s lawful to kill the innocent), the answer to this question isn’t as significant as the reasoning that supports it. Of course Thomas says that accidental killing is not the same as murder. Why?

The main idea is that sin is a moral evil, which means that a sin is an act that is not in accord with right reason and eternal law—“not in accord with” signifies lack or privation or deficiency, which is the essence of evil, and “right reason and eternal law” indicate that the evil is moral in nature, as opposed to physical or metaphysical. (For more on these distinctions, see Thomas’s Quaestiones disputatae e malo (Disputed Questions on Evil); Regan has a good translation.) As a morally bad thing—note that Thomas includes the notion of offense against God in his definition of “moral”—a sin essentially involves a failure to follow right reason and the law of God. And as a morally bad act, a sin essentially involves a voluntary choice to disobey right reason and the law of God.

To summarize: In order for an action to be sinful, it must be a voluntary choice to go against right reason and the law of God.

Thus, an accidental killing is not murder because it is not a voluntary choice. As Thomas quotes from Aristotle: “chance is a cause that acts beside one’s intention.” So killing someone by chance (or accidentally) is by definition beside one’s intention, and as we’ve seen throughout this question on killing, especially in the article on self-defense, it is one’s intention that makes the (moral) difference. I think it’s clear, but it should be said anyway, that the outcome of an accidental killing is still bad, even though the person who caused the accidental death has not done a morally evil act.

I hope what has been said so far is clear because Thomas is about to make things a little more complicated. Or, I should say, Thomas isn’t making things more complicated; he just recognizes that things aren’t always this simple.

Here’s the complication. Thomas says, “Nevertheless it happens that what is not actually and directly voluntary and intended, is voluntary and intended accidentally, according as that which removes an obstacle is called an accidental cause. Wherefore he who does not remove something whence homicide results whereas he ought to remove it, is in a sense guilty of voluntary homicide.”

For the Latinists among us, I should note that Thomas’s Latin in these two sentences is a bit unclear. In particular, it’s not clear how to understand the words “removens prohibens” in the first sentence: “Contingit tamen id quod non est actu et per se volitum vel intentum, esse per accidens volitum et intentum, secundum quod causa per accidens dicitur removens prohibens.” The gist of the passage seems to be that accidental intention happens when someone removes something they ought not to, that is, something that is prohibited for one to remove. But in the next sentence Thomas says that if someone does not remove something they should remove and homicide results, the person who did not remove what should have been removed is in a sense guilty of murder. What I think Thomas means is that if you remove an obstacle to someone’s death that you ought not have removed, then you are “in a sense” guilty of murder.

Posted by Gary Hartenburg