The Myth of Perfect Knowledge
Science will never be able to give a completely objective description of the world. That should make us humbler—and wiser.
The modern world owes a lot to the Enlightenment, the 18th-century intellectual movement that emphasized the power of reason. But the Enlightenment also created a myth: that we can get to know the objective world completely, with total clarity, as if we were looking at it from the outside. This myth is challenged by the Enlightenment’s greatest legacy—modern science.
Reality is more complex than we expected. Physics—my trade, and perhaps the most objective among the sciences—questions the possibility of a full description of how things objectively are. An electron can be in a “quantum superposition,” so that to an observer, it doesn’t occupy just one location—and so can you, my reader. This does not mean that you could perceive being dislocated between two positions; as perceived by yourself, you are always in just one place. But an object’s properties may differ depending on who, or what, is looking at them—or may not even be defined at all. Properties are not simple features of things: They are relations between one thing and another. What we call “the world” is therefore only how some parts of reality manifest themselves to other parts—us, for instance.
Humanity has always been aware that our understanding is partial and biased. But the fact that an objective and knowable reality is incompatible with the grammar of physics is astonishing. The Enlightenment could consider the mind as being outside the world, in an abstract realm of reason where knowledge resides. But human minds are not outside reality, watching it from its exterior. We, like everything else, are part of the very nature we study.
Our knowledge is only one example of the many correlations that intertwine different parts of nature. In the early 20th century, Niels Bohr, a founder of quantum theory, realized that quantum phenomena indicate that we cannot discard our own physical nature when we observe the world. The ideal of grasping objective reality by making the observer irrelevant is incompatible with physics. We are quantum processes interacting with other quantum processes. Our knowledge is a rich but incomplete set of correlations between one piece of the world–ourselves–and the rest of it.
To see this fact from another point of view, consider saying “It’s raining and Ann does not know it.” This makes sense: You know that it’s raining and that Ann doesn’t. But if you replace “Ann” with a first-person pronoun, the result is odd: “It’s raining and I do not know it.” How can you declare that it’s raining if you do not know it? This observation points to the fact that every proposition can only express the knowledge of the speaker or writer. No proposition is asserted from outside reality, because there is nothing outside reality. To say “It is raining” is really to say: “I, as part of reality, know that it’s raining.” Objective statements independent of any knower are fictions. Purely objective reality is a useful myth, but only a myth. Anything said about the state of the world comes from someone’s singular perspective.
This means that all of our knowledge is intrinsically uncertain. All statements have unavoidable margins of uncertainty. Indeed, we can be wrong about anything, even the basic facts of our own lives. My father grew up sure that his first name was Franco until he asked for a copy of his birth certificate and found out that my grandfather, without telling my grandma, had registered him as Giulio. He had been wrong about his own name. Humanity has been collectively wrong over and over again. We thought the sun moved around the earth, then learned that it is the earth that orbits the sun. Great scientists are even more likely to be wrong than others, because they have the courage to try—Einstein’s published work includes many mistakes.
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But in science, as in daily life, we do not need certainty; being reasonably sure is good enough. If I have an airplane to catch, I will go to the airport even though I’m not totally sure that the flight will take off; if I waited for certainty, I’d never leave home. Modern science offers an enormous body of knowledge that is effective and, in many domains, far better than all the alternatives, but it gives us no absolute certainty, no ultimate story, no Truth with a capital T.
Within science, there are different ways of describing the same things. A glass of water can be described in terms of physics (its mass, velocity), thermodynamics (its temperature), chemistry (there is more than just H2O in any glass of water), biology (bacteria swim in it), particle physics (its electrons, protons, and neutrons), psychology (“Why did I fill the glass?”), economics (its price), and more. Each account is valid in its own terms; each reflects a way in which the same object interacts with different parts of reality, from atoms to the global economy. But none exhausts an “ultimate truth” of the glass.
The same is true for human beings. I can think of you, my reader, as a body, as a mind, or as a soul. These aren’t different entities: They are the same entity, described in different languages, using different conceptual schemes, focusing on different aspects of the same you and different ways in which you interact with other parts of reality. There is no sharp separation or metaphysical gap between body and soul; matter and spirit; the physical world and the world of laws, ideas, and norms.
In this sense, all things are equal: They are all aspects of the same natural world, considered from different perspectives, none of which is the ultimate one. Everything can be considered fundamental from one perspective or another. The expression “the equality of all things” comes from the title of the second chapter of The Book of Zhuangzi, one of the greatest books of humankind—an ancient classic of Chinese philosophy that articulates a similar intriguing perspectival and anti-foundational naturalism.
This is the view to which I think modern science leads us. Many people resist it, some out of fear of losing solid reference points: objectivity, certainties, absolute morality, an immortal soul. But scientific knowledge does not become less valuable if you remain open to doubt. Morality does not lose power if you recognize that it is rooted in our biology, culture, and history. Our values do not weaken because they are rooted in what we are, not in something outside us. And life is even more beautiful and precious without dreams of immortality. We are not—as French existentialism described us—thrown into alien nature. In nature, we are home.
In fact, it seems to me that recognizing the perspectival aspect of knowledge, values, and beliefs, and of reality itself, could help us become a bit less arrogant, a bit humbler and wiser. Conflicts between individuals or countries don’t stem only from greed and thirst for power. They are also fueled by the belief that we are objectively right and the enemy is objectively wrong, which ignores the plurality of perspectives. We have our values that guide us, but understanding the perspective of others is the first step toward wisdom—and toward peace. In our era of nuclear armaments, ignoring that others have different perspectives, and failing to respect them, could drag the world into a catastrophe.
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