Pluralism: Beyond the One and Only Truth
Other than the fact that there’s a lot going on in it, I’m not sure how this shot of the Hoboken waterfront relates to pluralism. I just like it.
August 12, 2023. This is a free, updated version of a column I originally wrote for ScientificAmerican.com, which makes a nice follow-up to my profile of philosopher Paul Feyerabend. –John Horgan
Here’s how science works: Scientists have different, contradictory ideas about why stars shine, or how traits are passed from one generation to the next. After lots of observations and experiments, scientists figure out which idea is right. They converge on the truth, embodied by quantum mechanics, evolution by natural selection, the genetic code.
So I used to believe. I was what philosophers sneeringly call a naïve realist, who thinks scientific questions have a single, correct answer, which reflects reality, how things really are. But my views have shifted. Now I suspect that certain big questions might not have a single, definitive answer. They might have lots of answers. This possibility, which I once considered oxymoronic, is called theoretical pluralism.
Take, for example, the mind-body problem, which addresses how matter generates mind, and especially conscious states. When I first started writing about the mind-body problem decades ago, theorists such as Francis Crick, Gerald Edelman and Roger Penrose were proposing different solutions. If one of them was right, I assumed, the others had to be wrong. They couldn’t all be right.
My view has evolved. In Mind-Body Problems, I argue that there is and never will be a single, objectively true solution to the mind-body problem. There are many and maybe even an infinite number of solutions, including ones still unconceived. You may prefer an information-based theory or a strange-loop model, but your choice is subjective, a matter of taste, not truth.
Physics provides another example. In What Is Real? The Unfinished Quest for the Meaning of Quantum Mechanics, Adam Becker recounts efforts to understand, or interpret, quantum mechanics. What does quantum mechanics really tell us about the world? About the nature of matter and energy, time and space, causality?
“There is a correct interpretation” of quantum mechanics, asserts Becker, who was trained in astrophysics, “though it may not be any of the ones that we have yet.” I disagree. My recent quantum experiment has convinced me that there isn’t a “correct interpretation” of quantum mechanics, any more than there is a correct way to look at the world. There are many possible ways, each with its pros and cons.
One advocate of this view, called theoretical pluralism, was 19th-century physicist Ludwig Boltzmann. Science doesn’t give us truth, Boltzmann argues, it gives us representations, or models, each of which is necessarily limited. Hence we can never be sure that any given model is true. Boltzmann says the scientist’s goal should be
not to discover an absolutely correct theory, but rather to light upon some constructive model which shall be as simple as the circumstances permit and represent the phenomena most adequately. In fact, it is not inconceivable that two quite different theories should exist which are equally simple and accord equally well with the phenomena, and which therefore, although they are totally different, are yet equally correct. The assertion that a given theory is the only correct one is merely the expression of our subjective conviction that there is no other theory so simple and according so well with the facts.
That strikes me as a sensible plea for open-mindedness, which can prevent us from being trapped by our certainty. A more modern pluralist is Paul Feyerabend, one of my all-time favorite thinkers. For him, pluralism is a moral and political issue. He loathes attempts to reduce the world to a single, ultimate explanation, a “theory of everything” that all of us should accept. He equates this endeavor with totalitarianism. Feyerabend defends our right to believe in myths and theologies that lack empirical support. He writes:
Human life is guided by many ideas. Truth is one of them. Freedom and mental independence are others. If Truth, as conceived by some ideologists, conflicts with freedom, then we have a choice. We may abandon freedom. But we may also abandon Truth.
Once, when I stuck up for scientific knowledge, Feyerabend responded, “What’s so great about knowledge?” Although I share Feyerabend’s distaste for scientific hubris, my pluralism is less radical than his. I’m inclined to rule out theories, such as young-earth creationism, contradicted by massive amounts of data. Nor do I have any tolerance for morally abhorrent, pseudoscientific ideas, such as ones that proclaim the innate superiority of one race or gender.
But that still leaves plenty of cases when pluralism is appropriate. In many situations, we should think like engineers, who are natural pluralists. Faced with a problem like building a new bridge, electric car or smart phone, engineers don’t ask, What is the definitive, ultimate, true solution to this problem? That sort of thinking would be counterproductive. The engineer’s job is to find a solution that works.
A solution can work in lots of ways. It can give us power over nature, or over ourselves. It can help us make sense of data and predict the outcome of experiments. On a more personal level, an answer can console us, give us meaning, help us make sense of our lives. It can amaze us, tearing the scales from our eyes so we see the world anew.
That brings me to philosophical fabulist Jorge Luis Borges. In his story “Tlon, Uqbar, Orbis Tertius,” Borges toys with theoretical pluralism, although he doesn’t use that phrase. The story imagines a world whose sages have concluded that reality is irreducible and inexplicable. That assumption, far from discouraging speculation, inspires it. Tlon’s thinkers propose countless models, or “systems,” that are “beautifully constructed or sensational in effect.” Borges continues:
The metaphysicians of Tlon are not looking for truth, nor even for an approximation of it; they are after a kind of amazement. They consider metaphysics a branch of fantastic literature. They know that a system is nothing more than a subordination of all the aspects of the universe to some one of them.
Borges, that sly dog, notes that in Tlon the most fantastic system of all is “the doctrine of materialism,” which holds that matter has an objective existence apart from human perception. Materialism is so counter to the mindset of most Tlonians that they simply do not understand it, no matter how cleverly it is propounded. (I know Earthlings who feel the same way. And I’m an old acid head, so I toy with mystical notions myself now and then.)
I suspect our debates over materialism, the mind-body problem and the meaning of quantum mechanics will never be resolved. Neither will our debates over God and free will, the epistemological status of moral or mathematical claims, the origin and ultimate destiny of the cosmos, the possibility of other universes. These conundrums are strands within the big, knotty meta-mystery of our existence. We should be grateful that this meta-mystery does not have a single, objectively true solution, because that means we can keep inventing new solutions, solutions that astound us, that make us see the world anew, forever.
Postscript: Thanks to my pal Richard Gaylord, a physicist and Boltzmann fan, for encouraging me to write about pluralism.
Further Reading:
My Encounter with Philosophical Anarchist Paul Feyerabend
Thomas Kuhn’s Skepticism Went Too Far
On God, Quantum Mechanics and My Agnostic Schtick
Conservation of Ignorance: A New Law of Nature
My books Mind-Body Problems and My Quantum Experiment explore pluralistic themes.