Our fickle age usually welcomes the new, the original, the untried. But no one I know places the “novel virus” Covid-19 in a happy category, and rightly so. The pandemic has led us to live—and sadly in some cases, end—our days in modes novel to us, but to paraphrase Yeats, with this virus “a terrible newness is born.”

Meanwhile, researchers and doctors all over the globe race to find methods and treatments to ameliorate the virus’s symptoms and effects, test the extent of its spread, and ultimately move us beyond its malevolent reach through a vaccine. And that means most of us daily read and view and hear accounts of the scientific method in action—for example, testing the efficacy of treatments already prescribed for other ills, such as last week’s frontrunner, the newly promising Remdesivir, or evaluating the rates of false positives and false negatives of various virus or antibody tests. As a result, many of us now semi-knowledgeably pontificate about virus replication, testing parameters, and why it is necessary to subject vaccines to a time-consuming series of trials. After weeks of such online education, although I don’t know much about how the kids’ remote-learning grasp of STEM (science, technology, engineering, and math) subjects is going, the medical and chemistry education of news-chasing adults is proceeding apace.

According to the scientific method, you learn what works and what doesn’t through experimentation. Ideally, you set up a control group and an experimental group, and compare outcomes to gauge the effect of the variable you are studying (say the vaccine) on the fortunes of the experimental group. In medical science, to sidestep the placebo effect and other factors related to the researchers’ inherent biases, the purest type of experiment is a double-blind study, where neither the researcher nor the subject knows which persons are actually receiving the studied intervention as opposed to receiving a lookalike that should have no effect.

Recently, the abortion-related Covid-19 pandemic controversies erupting in some states led me to meditate upon the scientific method and its strengths and limitations. Because of the strain to our healthcare system, states with many Covid-19 cases have forbidden elective or relatively minor surgeries until local manifestations of the pandemic calm down. The question then arises (not to prolifers, of course, but certainly to Planned Parenthood) whether abortions qualify as necessary medical procedures. Only a small percentage of abortions are performed even ostensibly for the health-of-the-mother, though many expectant women in crisis would argue that their emotional health would be adversely affected by bringing the baby to term, or that the child’s projected poor quality of life makes death in the womb preferable.

But science, purely as science, has nothing much to say about such issues. In fact, it is of little use in determining in general how human beings should act—that is, how they are to make prudential judgments about what would produce the happiest result and how they are to make moral judgments about what would be the right thing to do.

One of those feel-good we’re-all-in-this-together TV network ads recently pronounced that we all need to seek the greatest good for the greatest number. I think the network’s intended message was along the lines of temporarily sacrificing our mobility and personal liberty to protect vulnerable people from infection. The speaker may also have been contemplating triage decisions: Who gets the ventilator, and when should you pull it out to move on to a more promising candidate?

Regardless, it seems as daft a statement as it did when I encountered it as a student in Intro Psych. First, because it glides over what any of these terms even mean—greatest material good? Greatest psychological or emotional good? Greatest good in duration or intensity, or in hierarchy of value? But beyond all that, the statement assumes we know, as we do not with any certainty know, which decisions would create the conditions for the greatest good for the greatest number.

We can’t even identify all variables and contingencies, let alone control for them to observe what happens when you vary these few, because we can’t ensure that only those few will be varied. Almost 80 years after the Great Depression, historians and economists argue about which actions or inactions were most responsible for setting it off, and which responses might have abbreviated its duration or better moderated its intensity. Nowadays, as we know all too well, we grapple with dozens of models of the course that Covid-19 is likely to take in our own country and around the world, with varying outcomes partly based on human actions but also based on how very much we don’t know about the virus’s nature, range of effects, and ability to conceal itself in the asymptomatic.

The obvious lesson for us should be that it’s hard to achieve a God’s-eye view of human history—that is, one that can account for all occurrences and interactions and their relationships and effects on each other—with perfect and complete intelligence. That is one reason why lovers of sci-fi and superheroes gravitate to the topics of time travel and alternate universes, where you supposedly get to see what happens to people under different circumstances.

The reality we limited mortals live with in our own particular universe, whether we admit it or not, is that, even in our individual lives and our day-to-day decisions, we cannot construct anything close to a controlled experiment that will assure us, on the basis of the outcome alone, of the best choices for our own happiness or that of those around us, let alone the happiness of the human race or Mother Earth. Do we judge by short-term results, or middle-term, or long-term? Do we seek out concentrated happiness, or moderate happiness leavening a lifetime, or a grand finale of satisfaction at the point of death? How do we weight prosperity, health, leisure pursuits, relationships, and career?

We can rate these conditions any way we choose, but however we do so we should recognize that our individual algorithms are partial and imperfect and do not qualify as “scientific” rankings. Even controlled experiments exploring such decisions can only offer partial and imperfect insights. (And these insights are revealed to be even less complete when we consider the possible effect of our earthly actions on an afterlife into which the laboratory and its methods apparently cannot enter.)

These distinctions between controlled scientific observations and the often wildly uncontrolled experiment called life help explain the place of natural law in ethical decision-making. Flow-charts have their place, and we all gain by learning to exercise prudence and cultivate wisdom. The immediate and foreseeable effects of our actions rightly aid us in navigating prudential decisions about what we should do in a given situation. But these are guides to choosing among non-evil options, rather than rigid yardsticks by which to measure correct decisions. Arriving upon the morally right choice is too important to entrust entirely to utilitarian or consequentialist thinking. Our choices, after all, affect not only the partly apprehensible fate of ourselves and others but also our own moral character and, many of us believe, our eternal destiny.

So the expectant mother in crisis may legally allow fear and pain to move her to abort her child, but whatever the arguments of those around her, this decision cannot be legitimately validated by science or lifeboat ethics or any other institution or construct based on the false belief that we can trace all consequences and control for all variables. If we make moral decisions purely on our perception of material and psychological consequences, we will never know whether we have acted rightly or wrongly. We cannot see that far or that wide or that deep. If we make the best moral decisions we can on the basis of the moral absolutes our human nature has been endowed with, we will inevitably at times fall into prudential errors, but for the most part avoid instances of doing evil that (as the consequentialists advise us) good may come of it.