On Tuesday morning, Patrick S. Tomlinson, an author of science fiction and fantasy novels and contributor to the New York Times, tweeted out a challenge to the “pro-life crowd,” a challenge that, to Tomlinson’s satisfaction, demonstrates that these people pay mere lip-service to the idea that life begins at conception. Deep down, Tomlinson says, no one really believes an embryo is a human life.

According to Tomlinson, he has been posing this challenge for ten years, and “no one has EVER answered it honestly.” He announced this challenge with the glee of an inventor, yet what’s funny is this challenge has actually been around far longer than 10 years, and is a fixture within the field of applied ethics.

So what is Tomlinson’s challenge? What is the ethical scenario he insists both “destroys” and “eviscerates” pro-life arguments? Here it is:

“You're in a fertility clinic. Why isn't important. The fire alarm goes off. You run for the exit. As you run down this hallway, you hear a child screaming from behind a door. You throw open the door and find a five-year-old child crying for help. They're in one corner of the room. In the other corner, you spot a frozen container labeled ‘1000 Viable Human Embryos.’ The smoke is rising. You start to choke. You know you can grab one or the other, but not both before you succumb to smoke inhalation and die, saving no one. Do you (A) save the child, or (B) save the thousand embryos? There is no (C).”

Tomlinson says that in ten years he has never received a straight answer from a pro-lifer. Let me try to reconstruct his reasoning here:

(1) The pro-life position crucially involves the view that life begins at conception.

(2) If pro-lifers really believed life begins at conception, they would easily and unproblematically choose to save the thousand embryos over the single 5-year-old child.

(3) But if a pro-lifer was actually put into Tomlinson’s scenario, she would choose to save the child.

(4) Thus, pro-lifers don’t really believe life begins at conception.

(5) The pro-life position is a sham.

Tomlinson registers a deep frustration with pro-lifers who don’t offer him the answer he is looking for. Remember, in ten years no one has answered him “honestly.” Yet what would that involve? Well, what Tomlinson probably wants pro-lifers to say is something like this:

“Patrick, all of my life I have been in a kind of pro-life haze, a self-delusion. Your challenge has helped me see that I don’t really believe life begins at conception. You are right: I would save the child. But do you want to know someone else who has been saved? I have. Thanks for for issuing your challenge.”

But let’s explore why someone in the pro-life camp might hesitate to give Tomlinson this answer. Tomlinson thinks pro-lifers hesitate because they know this challenge eviscerates their arguments. Perhaps a parallel argument will be illustrative: Let’s consider a scenario involving a “standard liberal,” by which I mean someone who subscribes to a left-leaning politics in a very broad sense:

(1) The standard liberal position crucially involves the view that every individual has equal value.

(2) In a scenario roughly comparable to Tomlinson’s, where a standard liberal had to choose between saving 100 random people, or their own spouse or child, someone who believed that every individual has equal value would easily and unproblematically choose to save the hundred random individuals.

(3) But if a standard liberal were actually put in such a scenario, he would choose to save the family member.

(4) Thus, standard liberals don’t really believe every individual has equal value.

(5) The liberal position is a sham.

I suspect Tomlinson would not like the result here. But does that chain of reasoning “destroy” and “eviscerate” the liberal framework of human equality?

No. Because both “challenges” are flawed.

The problem is that in crisis situations our decisions don’t inexorably follow what we believe to be right.

One of the most famous thought experiments, in both philosophy and law, is the so-called Trolley Problem. I’ll construct it a certain way in order to set up another parallel:

A trolley (a train) is set to kill five people who are stuck on the tracks unless you pull a lever that derails the trolley onto another set of tracks which will kill only one person. Let’s assume all six people — the five on the first set of tracks and the one on the second set of tracks — are morally on a par. Meaning that it’s not like the five are convicted rapists and the one is on the verge of curing cancer. Most people conclude that if they were in that situation, they would pull the lever. Their reasoning is simple: if we have to choose, saving five lives is preferable to saving one.

At this point Tomlinson might be tempted to claim victory. He might point to the fact that this is a clear cut case in which our belief that five human beings should be prioritized over one human being (assuming, again, that they are on equal footing) leads us to actually choose to save five over one.

In other words, the fact that we really believe we should save five over one leads us to actually doing it—or at least saying that we would do it.

Not so fast.

Because what if we modify the trolley scenario ever so slightly?

In this modified scenario, there is no lever. You remain the only way for the five to be spared, but the mode of activating this choice has changed. You know enough about trains to know that someone of your size cannot stop the train from hitting the five. But you also know perfectly well that a person who is nearby—a very fat man—can be pushed in front of the train. And although he would be killed, his body would stop the train before it could crush the five people stuck on the tracks.

Many people who say they would pull the lever in the first scenario then say they would not push the fat man in the second scenario.

Why?

In both cases, you sacrifice one to save five. In both cases, the lone individual would be safe if not for your action. The utilitarian features are the same, so why are some people fine with killing the single individual in the first scenario but not in the second?

Because pulling a lever is an action that is disassociated with violence, whereas pushing a person into an oncoming train is inherently gruesome. Here, then, is what is key: When we choose to refrain from pushing the fat man, we are not thereby nullifying our belief that we should save five over one. Rather, something else is happening: Something is interfering with our belief. Our disinclination to violently kill an individual overrides our belief that saving five is better than saving one.

This reasoning is a standard feature of human beings. If I rattle off statistic after statistic about world hunger, you might be moved to take action. Yet there is a very good chance that those numbers — welcomed as mere abstractions, mere statistics — won’t come anywhere close to the impact it might make on you if I were to bring a malnourished child to your doorstep.

Does this differentiated response—which is objectively imbalanced given that entire villages suffering hunger is uncontroversially worse than an individual suffering hunger—indicate that you think one life is worth more than thousands?

Obviously not. Yet you could run a Tomlinson-style “challenge” to demonstrate this very idea. Would this “eviscerate” the argument that thousands of lives are more important than one? Of course not.

And the reason is because our emotions, reactions, choices, are not always (and that is putting it generously) directed toward what philosophers and economists call the “optimific” outcome. Our systems routinely run interference against a simple utilitarian calculus. The belief we all share that a thousand lives should be prioritized over one runs headfirst into the emotional impact of witnessing the suffering of the one up close and personal. But this does not mean that we think one life should be seen as more valuable than a thousand.

Why might I, personally, lead the child to safety in Tomlinson’s scenario, rather than rescuing the thousand embryos? Because I would not be able to stare into the eyes of a child in perfect fear and pass him by. The embryos cannot do anything, in their present state, to match the terror and the dread of a child about to be engulfed by the flames. Let the thousand human lives haunt me afterwards; in this moment, they cannot haunt me more than seeing a helpless child be swept up in a fire.

This does not nullify my belief that life begins at conception. What could be more human than for our actions to fail to live up to what we know is true and right?

Berny Belvedere is editor-in-chief of Arc Digital.