Why science?

Part two of a three-part series on universities, science, and the promotion of health as our social purpose.

Last week’s Healthiest Goldfish essay was the first in a series of three essays about the process of knowledge generation that is at the heart of all we do in public health. In that essay, I considered the role of universities in this process and how we can strengthen and sustain universities in a time when they are being challenged. Today, I would like to engage with another essential element of knowledge generation: science.

I have been mulling this piece ever since a fireside chat-style conversation I facilitated with John Ioannidis at the 2026 Society for Epidemiologic Research meeting. After a lengthy discussion about the shortcomings of science, I asked him why—given the severity and persistence of some of these shortcomings—bother with science at all? His answer: because it is the best thing that we can do for homo sapiens sapiens. The answer has stayed with me ever since, and this essay is, in part, an attempt to think it through. Ioannidis is the author of what may be the most-read methods paper of this century, “Why Most Published Research Findings Are False,” and he is perhaps the field’s most famous (and at times controversial) internal critic. That the person who has done as much as anyone to expose science’s fallibility still calls it our species’ best endeavor is not a contradiction; it is, to my mind, an essential point about why science is indeed indispensable. The willingness of science to interrogate itself, to take a reasoned look at its own strengths and weaknesses, is precisely what makes it worth pursuing and defending.

So, in the spirit of this interrogation, “why science?” Why does it matter that we do it, fund it, teach it, trust it? And why science now, at a moment when science’s funding, standing, and store of the public’s trust are all contested?

A point of clarification before I tackle this. I do not address here the related, but different question of “what” is science? There is a long intellectual tradition of thinkers from Bacon to Karl Popper to Richard Feynman to Robert K. Merton and even to Vannevar Bush’s Science, the Endless Frontier who have discussed this. Fundamentally, my take is science is not a set of answers, but a discipline committed to uncovering, and communicating, truth.

How does such a discipline then go about elevating our species? I would suggest it does so in two ways.

First, science improves health by helping create the material conditions in which all can live better, healthier lives. At the most intuitive level, where health is concerned, this refers to the many treatments for which science is responsible, treatments which have made a world-changing difference in the health of populations. We saw a dramatic example of this during COVID, when science helped to quickly deliver a vaccine, shortening the acute phase of the pandemic and saving countless lives. That was just one chapter of the broader story of vaccines, a story in which science has created the lifesaving medications which have transformed our species’ relationship with disease, making contagions far less deadly, and even eradicating smallpox, a disease which killed 300 million people in the 20^th century alone.

Science has also improved health at the material level by helping to create the modern world—a world in which feats of progress like the harnessing of electricity, improvements in sanitary infrastructure, the application of scientific techniques to agriculture, and the still-unfolding digital revolution have made life longer and better for nearly every human being on earth. Science, whether directly or indirectly, has underwritten just about all of the material progress that has characterized the 20^th century, a century which saw the doubling of global life expectancy—a core metric (perhaps the core metric) of progress on health.

Science has not just made human life better, it has, arguably, helped make human beings themselves better. This is in part because of the values of science, the core principles that allow for the reasoned pursuit of truth. They include honesty (because the data are what they are), patience (because science is a long game, sometimes taking generations to yield a breakthrough), and humility (because the findings of even the most accomplished scientist may turn out to be false). These values help advance a scientific endeavor which can then present a picture of the world that is evocative of those very values. It is difficult, for example, to view the images of outer space science has allowed us to access without a sense of humility and a longer-term outlook on human life that lends itself to greater patience. And the essential role of truth in science is a reminder of the power of truth generally, of the necessity of keeping it always at the heart of all we do.

There are, of course, limits to science’s capacity to uplift humanity at the level of values. Science can also create the conditions for great harm. One of the central scientific developments of the past century, for example, is the atomic bomb, which has the power to end life on earth. It is for this reason that I have long argued, echoing the work of moral traditions, of philosophy, and of the humanities, that a moral case for health should exist alongside an empirical one. The work of science should be pursued in tandem with the work of building a philosophical framework for science to do the most good and to avoid where it can go wrong. This is, in part, the aim of these essays—to help shape a way of thinking about science that enables it to be at its best, to continue yielding the fruits that have done so much to improve life for us all.

Even as I, admittedly, elevate science, it is important to acknowledge that science cannot solve all the world’s problems. Nor is the work of science the end-all-be-all of human endeavor. Humans also love, make community, worship in their different ways. Such pursuits are as old as they are core to the human experience, and we should not think of science as somehow a candidate to replace any or all of them. Yet science remains one of the best things that we as humans do and, in doing science, we make a unique contribution which makes the world a better place in ways we would not want to live without. This is why I return to the question of why science and to the answer, in compressed form, of: science is the best thing we can do for homo sapiens sapiens because it is also something that only homo sapiens sapiens can do.

For these reasons, science is bigger than any one person or institution, and when we occasionally see the fallibility of the people and organizations tasked with the work of science, this should not be cause to doubt (or defund) science itself. Rather, such times are moments to return to what science really is, what it has given our species. When we do this, we can see the value of science as very nearly self-evident. Science is worthwhile because a better world is worthwhile and we cannot get to such a world without the work of science— nor should we try to.

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Also this week

In The Lancet Regional Health – Americas:

Pre-existing financial circumstance, job loss, and probable depression among U.S. adults: a prospective population-based cohort study – with Leila Mady, Grace Ringlein, Rajesh Satpathy-Horton, Elizabeth Stuart, and Catherine Ettman

Thank you, Leila, Grace, Rajesh, and Elizabeth, for your partnership on this work, and thank you, Catherine, for leading it.