To Do Proper Science, You Have to Be a Realist - David Deutsch

Introduction

What is reality, and why must a scientist be a "realist" about it? These questions strike at the heart of scientific philosophy. Reality can be defined as the sum total of all that truly exists – “the aggregate of all that is real or existent… known and unknown”. In other words, reality includes not only the things we directly perceive, but also those unseen entities and processes that exist independently of our minds or observations. Scientific realism is the doctrine that science’s goal is to describe this objective reality as accurately as possible. According to this view, the universe described by science exists independently of our perceptions, and well-tested scientific theories are at least approximately true descriptions of that reality. Crucially, scientific realism asserts that we can legitimately talk about unobservable entities (like electrons, fields, or other universes) as real, not merely as convenient calculational tools.

The statement “to do proper science, you have to be a realist”, attributed to the physicist David Deutsch, encapsulates the idea that science can only flourish when it earnestly aims at truth about the real world, rather than treating theories as just abstract games or instruments for prediction. In this essay, we will explore what it means to be a realist in science, how reality is defined and understood, and why a commitment to realism is essential for scientific progress. We will examine the pitfalls of anti-realist or overly skeptical philosophies that arose in the 20th century – those “bad philosophical reasons” Deutsch warns against – and see how they can derail our understanding. Through historical and modern examples (from the atomic theory to quantum mechanics), we will illustrate that embracing reality is not only philosophically sound but practically fruitful. Ultimately, the pursuit of truth about reality is more than an academic exercise: it is what enables science to uncover profound, meaningful truths about nature – truths that can enlighten our consciousness and empower humanity.

What Do We Mean by Reality?

Reality in the broadest sense means everything that actually exists – physical objects, forces, energy, space and time, and even abstract entities if they have real effects. It stands in contrast to illusion, imagination, or mere appearance. For example, the Earth, the Moon, and the atoms that compose them are part of reality; a mirage on a hot road or a dream at night, while experiences, do not correspond to something real in the external world. In everyday life we often equate “real” with what we can see or touch, but scientifically we’ve learned that much of reality is hidden from our senses. Atoms and molecules, germs, radio waves, the curvature of spacetime – these are all real phenomena that we cannot observe directly with our unaided senses, yet we know they exist through theory and experiment. Reality thus includes both the observable and the currently unobservable (or not directly perceptible). As one reference puts it, reality in physical terms is “the totality of a system, known and unknown”.

To understand reality means to construct mental models or theories that correctly describe what exists and how it behaves. This is where science comes in. Science is, at its core, “a project of understanding the world – understanding what there is and how it behaves”, as Deutsch emphasizes. Implicit in this mission is the assumption that there is a real world to understand in the first place. This might seem obvious – of course the world exists! – but in the history of ideas, not everyone has agreed on how confidently we can speak of an objective reality. Before delving into why realism is vital, let us clarify the term “realist” in the scientific context:

• Scientific Realist: Believes that an external physical reality exists independently of observers, and that scientific theories aim to describe this reality (including aspects beyond direct observation) with increasing accuracy. A realist holds that terms like “electron”, “DNA”, or “black hole” refer to real entities out in the world (not just useful concepts), and that a theory’s success indicates it is capturing some truth about nature. Realists expect that unseen causes (whether subatomic particles, fields, or other universes) can be real, if they explain the evidence.
• Instrumentalist or Anti-Realist: Views scientific theories as mere tools for organizing observations and making predictions, without committing to their being true or their entities being real. For an instrumentalist, it might be meaningless or unnecessary to ask if electrons “truly exist” as long as the theory predicts experimental results. In extreme forms, an anti-realist might claim that only the observable phenomena are meaningful, and anything unobservable is speculative or "just a model."

The tension between these views isn’t just semantic – it affects how one does science. If one believes reality is out there to be discovered, one will eagerly devise experiments to peek at the unseen, posit bold new entities, or refine theories to better mirror truth. If one believes reality stops at what we directly see or that searching for deeper truth is futile, one might restrict science to only description of surface phenomena, avoiding talk of what might lie behind them. David Deutsch’s contention is that “proper science” demands the former mindset – a commitment to an objective reality that science can progressively know. This commitment underlies the greatest breakthroughs in science’s history.

Scientific Realism: The Guiding Principle of Science

At first glance, scientific realism may sound like common sense. Indeed, for centuries science progressed under the straightforward assumption that we were uncovering reality’s truths. Isaac Newton, for example, certainly considered that his concept of gravity referred to a real effect of masses, and that planets really exist and move according to physical laws – even if gravity itself was an invisible influence. Michael Faraday and James Clerk Maxwell, when they formulated the electromagnetic field, believed they were describing a real, physical field filling space – not merely a mathematical fiction. This common-sense realism holds that what science reveals – atoms, viruses, energy, etc. – is genuinely out there. As the Stanford Encyclopedia of Philosophy notes, scientific realism is basically “the common sense conception” that science, when successful, uncovers true (or approximately true) knowledge about nature, including aspects not directly observable.

Why is this principle so critical? Because it is the only philosophical stance that truly encourages us to seek deeper explanations for what we observe. A realist attitude says: if something affects what we see, even if we can’t see that thing itself, we should consider that it exists and try to understand it. This was exemplified by scientists like Maxwell – he could not see electromagnetic waves with his eyes, but he postulated their reality from the indirect evidence and was vindicated when radio waves were later detected. Similarly, when early 19th-century chemists inferred the existence of atoms to explain chemical reactions, they were treating atoms as real objects (long before anyone could take a picture of a lattice of atoms). That belief guided experiments which eventually confirmed the atomic theory.

By contrast, if scientists had taken a strict anti-realist or positivist stance – “talk of atoms is merely a convenient shorthand, not to be taken literally since atoms are unobservable” – they might never have invested effort in experimentally confirming atomic reality. It is notable that in the late 1800s, the physicist-philosopher Ernst Mach did argue that atoms were just hypothetical constructs, “theoretical fictions” rather than real entities. Mach’s anti-realism made him skeptical of atomic theory. In hindsight, we know atoms are quite real (as Max Planck quipped at the time, atoms are as real as planets in their existence). Mach’s stance, while intellectually cautious, was a barrier to progress – it discouraged looking for deeper atomic evidence. It took bold realists like Ludwig Boltzmann (who defended atomic realism passionately) and Albert Einstein (whose analysis of Brownian motion in 1905 gave direct evidence of atoms) to firmly establish the atomic theory against that philosophical headwind. This episode illustrates a general pattern: when scientists assume that their theoretical entities might be real, they design ways to test and refine those theories, whereas if they assume “it’s not real, just a model,” the incentive to push further diminishes.

In sum, scientific realism fuels discovery. It tells us that our theories aren’t just convenient summaries of data – they are attempts to describe an objective world. A realist expects theories to fail if they are false, and thus treats predictive success as a sign that we’re onto something true, however approximate. This aligns with what philosophers call the “No Miracles Argument”: the success of science would be an inexplicable miracle if theories didn’t at least approximately latch onto reality. The realist perspective naturally leads to the view that later theories improve upon earlier ones, getting ever closer to the truth. For example, Newton’s theory of gravity wasn’t thrown out as a mere convenient fiction when Einstein’s relativity replaced it – rather, Newton’s law was understood as a very good approximation (useful in most everyday regimes) but not the final truth. Einstein’s theory, in turn, may one day be subsumed by an even deeper theory (quantum gravity, perhaps), but that doesn’t mean we abandon the notion that it describes something real – only that it will be recognized as an approximation to a deeper reality. In the realist view, truth with a capital T may be unreachable, but science can progressively approximate the truth. Each theory can contain real knowledge even if it isn’t the whole truth. As Deutsch succinctly puts it: “We only ever trust propositions that are strictly false, even though they may contain knowledge.” In other words, all scientific models are imperfect, yet we rely on them because they embody partial truths about reality that have survived rigorous testing.

It is important to clarify that being a realist does not mean being dogmatic or claiming infallible truth. Quite the opposite: a hallmark of scientific realism is fallibilism – the recognition that any theory can turn out wrong, but also that we can learn from error and move closer to truth. Karl Popper, a great philosopher of science who deeply influenced Deutsch, stressed that all knowledge is conjectural. We conjecture theories about reality and then test them; if they fail, we reject or refine them. There’s no final certainty, but there is objective progress: by eliminating errors we inch nearer to the truth. Deutsch echoes Popper’s outlook: “All human knowledge is false… So there’s no shame in being wrong. But there is shame in trying to short-circuit arguments… [and] settling into a fixed, unchanging worldview.”. Realism, paired with fallibilism, avoids both the Scylla of absolutism (claiming we have the Truth beyond doubt) and the Charybdis of relativism or nihilism (claiming there is no truth to find). Instead, it encourages an open-ended quest. As Deutsch explained in an interview, because there is the potential for unlimited progress, our current knowledge “hasn’t even scratched the surface yet” – indeed, “we’re all alike in our infinite ignorance”. This acknowledgment of ignorance is not defeatist; rather, it is, as Deutsch says, fundamentally optimistic: if we can be wrong, we can also improve. Fallibilism implies “there is such a thing as being right – that there is such a thing as the truth and that we can sometimes find some of this truth.”. In short, realism drives us to find truth, while fallibilism keeps us humble and open-minded in that pursuit.

The Perils of Anti-Realism: “Bad Philosophy”

If realism has proven so fruitful, why would anyone reject it? As Deutsch notes, during the 20th century many thinkers started questioning the straightforward realist stance of science. There were a few reasons for this, often stemming from philosophical missteps or overreactions to the fallibility of our senses and language. Deutsch calls some of these trends “bad philosophy”, not simply because they were incorrect, but because they tended to sabotage progress by declaring many deep questions off-limits. Let’s examine a few such ideas and why they are considered “dead ends” for science:

• Extreme Empiricism / Positivism: Early 20th-century logical positivists argued that statements about anything unobservable or metaphysical are literally meaningless. Only direct observations and measurement statements were considered valid knowledge. This led to a mindset that if you can’t see or measure X, you shouldn’t say X is real. While emphasizing evidence is good, the overly strict empiricist stance stifles theory. It would have us say, for instance, that talk of electrons or genes (before direct imaging existed) was “merely a convenient shorthand for observations, not a statement about reality.” Had this view prevailed strictly, scientists might never have confidently pursued the atomic realm or other unseen layers of nature. In effect, positivism tried to short-circuit scientific inquiry by drawing a line beyond which talk of reality was forbidden. Deutsch alludes to this when he notes that some philosophers asserted “we are only playing with words” and there’s no difference between a “truer” or “less true” theory. If taken seriously, that attitude means one theory cannot be objectively closer to reality than another – a recipe for intellectual stagnation.
• Radical Skepticism: Another thread was the idea that because our senses and theories can err, we “can’t have any knowledge” of an external reality at all. Yes, our senses are fallible – a stick in water looks bent when it isn’t, we see mirages, etc. But the radical skeptic concluded from this that all knowledge is hopelessly uncertain: maybe the external world doesn’t even exist outside our perceptions (a kind of solipsism or subjective idealism). In moderation, skepticism reminds us to test and doubt; but extreme skepticism becomes self-defeating. As Deutsch points out, earlier generations treated the thought “our senses can deceive us, so maybe we know nothing for sure” as an interesting paradox but did not let it halt their problem-solving. Yet in the 20th century, some philosophers started to take such skepticism very seriously, to the point of implying that science can never tell us what reality is, only how we perceive or talk about it. If one truly believed that, why bother trying to probe nature’s secrets? It undercuts the entire scientific enterprise.
• Instrumentalism in Physics (Copenhagen Interpretation): In no field was anti-realist instrumentalism more influential than in quantum physics. Confronted with the strange phenomena of quanta, Niels Bohr and the Copenhagen school advised physicists essentially to “shut up and calculate”, meaning: use the quantum formalism to predict outcomes, but don’t ask what quantum entities really are doing when not observed. Questions like “Does the electron go through both slits at once, or exist in many states simultaneously?” were deemed meaningless – only the observation outcomes were real. This is a classic instrumentalist posture: the theory (wavefunctions, superpositions, etc.) was treated as a mere calculational device, not a description of reality. While this pragmatic approach allowed rapid development of quantum mechanics as a tool, it left a conceptual void. Many physicists became content with the idea that quantum theory doesn’t describe an objective reality, only an observer’s knowledge. Einstein and others who asked for a clearer realist picture were often brushed aside as being “philosophical.” Over time, this created a strange situation: the most successful physical theory ever (quantum mechanics) was taught in a way that discouraged thinking about what is objectively happening in the quantum realm. Deutsch refers to this as an example of bad philosophy influencing science – a kind of learned intellectual timidity about reality. He notes that physicists grew inclined to say we can’t be sure of what’s outside our observations, taking an instrumentalist view that basically abandons the realist program.

The consequence of these anti-realist attitudes is, as Deutsch says bluntly, “not understanding anything.” That sounds harsh, but what he means is that if we adopt an intellectual stance that rules out the existence of deeper reality or dismisses the quest for truer theories, we stop asking the most important questions. We become satisfied with correlations and predictions and give up on explanation. Science, however, thrives on explanation – on finding out why things are the way they are, not just how to predict their behavior. When Bohr said “physics is not about how nature is, but about what we can say about nature,” he exemplified this anti-realist shift. To Deutsch (and many scientific realists), that sentiment is effectively an “agenda of not understanding the world.” It tells us to stop worrying about the true ontology behind quantum phenomena and just use the formulas. In the long run, such an agenda is “not worth having” because it relinquishes the most precious aim of science: to know reality.

Deutsch further argues that some anti-realist philosophies became “bad” in the sense of being actively hostile to new ideas. By asserting that no theory can be closer to truth, or that all we have is language games, they encourage a “fixed, unchanging worldview”. Any attempt to propose a novel explanation can be met with a shrug – why bother, since it’s all equally unreal? This is why he speaks of short-circuiting arguments on principle. Good science, and good philosophy, keep the conversation open, always allowing for criticism and improvement. Bad philosophy tries to preempt that process, perhaps from a cynical conviction that improvement is impossible or from some ideological agenda. The 20th century saw its share of such dogmatism, from extreme relativists who argued science is just a “social construction” with no special claim to truth, to others who declared “the debate is over” on certain fundamentals. All of these, in Deutsch’s view, undermine the ethos of discovery.

In summary, when science strays from realism, it risks losing its way. The known unknowns (things we know we don’t yet understand) and especially the unknown unknowns (things we aren’t even aware of yet) remain in the dark if we lose faith that there is a deeper reality to uncover. A realist mindset keeps us cognizant that behind our measurements and equations, something real is happening, and it urges us to find out what. An anti-realist mindset, in contrast, may lead us to declare certain questions “unaskable” or certain truths “unknowable” by fiat – effectively blinding ourselves to possible insights. It is a kind of voluntary intellectual captivity. Little wonder Deutsch implores us to break free of it and be unafraid to make conjectures about reality.

Realism in Action: Case Studies and Insights

1. Atoms and the Nature of Matter: We have already touched on the atom debate. This is a paradigmatic example of realism vindicated. For centuries, atoms were hypothesized (since the ancient Greeks) but with no direct evidence, one could only infer their reality indirectly. By the 19th century, the atomic theory explained chemical proportions and the behavior of gases (via kinetic theory). Yet skeptics like Mach insisted this was just a convenient model; he doubted that “atom” literally meant a tiny hard particle exists. Realists like Boltzmann suffered ridicule for insisting on atoms’ reality – tragically, Boltzmann took his own life in 1906, not long before experiments vindicated his stance. In 1908 Perrin’s experiments on Brownian motion (building on Einstein’s 1905 analysis) conclusively measured Avogadro’s number and showed particles the size of molecules jostling pollen grains – a direct confirmation of the atom’s existence. Reality, it turned out, was grainy at small scales, just as the realist scientists believed. The anti-realists were left behind, and science moved forward. After this victory, virtually all scientists became realists about atoms (indeed, chemistry and physics would make no sense otherwise). The episode taught an invaluable lesson: when a theory explains many disparate phenomena (e.g. gases, chemical reactions, diffusion) by assuming a hidden reality (atoms), it is rational to believe in that reality and investigate it further. Doing so led to quantum physics and all of modern chemistry. Had we clung to “only observables are real,” who knows how long progress would have been delayed?

2. General Relativity and Black Holes: Einstein’s general relativity (GR) in 1915 was a mathematically elegant theory of gravity that posited a dynamic spacetime curvature. Initially, one might have said, “okay, the math works, but is spacetime curvature real or just a model?” Einstein himself leaned toward realism: he believed gravity truly is the geometry of spacetime. An early prediction of GR was startling – the existence of “black holes” (then called frozen stars or Schwarzschild singularities), regions where spacetime curvature is extreme and not even light can escape. For decades, black holes were theoretical curiosities; even Einstein doubted whether nature would allow such bizarre objects. Some physicists treated them as perhaps just artifacts of the math. But over the 20th century, evidence mounted (quasars, X-ray binaries, gravitational waves) that black holes are not only real but common. The realist approach – taking the theory’s implications seriously and looking for them in reality – paid off. Today imaging a black hole’s shadow with radio telescopes is a triumphant confirmation that even the most extreme theoretical entities of GR correspond to something real in the universe. The instrumentalist who said “it’s just a math fiction” would have missed this wondrous piece of reality.

3. Quantum Mechanics and the Multiverse: Quantum physics, as discussed, posed a dire challenge to realism. The standard Copenhagen interpretation told physicists to avoid thinking of quantum wavefunctions as real physical waves – one was to treat them as abstract probability tools that “collapse” mysteriously upon measurement. But this left numerous paradoxes (e.g. Schrödinger’s cat, or particles seeming to have no definite properties until observed). A young physicist, Hugh Everett, dared to take the quantum math at face value. In 1957 he proposed what became known as the Many-Worlds Interpretation (MWI): that the wavefunction never collapses at all. Instead, all the possible outcomes encoded in the wavefunction actually happen – the universe branches into multiple copies, one for each outcome. In each branch, observers see one outcome, but the other outcomes occur in parallel, unseen by them. This was (and still is) a shocking assertion, implying a multiplicity of realities. Everett’s idea was largely ignored for decades, partly because it sounded like wild metaphysics. But David Deutsch and others later championed it, not as sci-fi speculation but as the only logically coherent, realist description of quantum mechanics. Deutsch argues that when we do a quantum interference experiment (like the famous double-slit experiment with single particles), the results force a realist to conclude something like many-worlds is true. For instance, if a single photon passes through a double-slit, we later detect one photon on a screen – yet we see an interference pattern build up as if that one photon went through both slits and interfered with itself. How can one particle interfere with itself? In the traditional view, one might say “well, it was a wave that went through both and then somehow collapsed to one spot.” But a realist analysis goes deeper: interference is a phenomenon of two (or more) waves interacting. If we only detect one photon, what did it interfere with? Everett’s answer: with its counterparts in the other branch of the wavefunction. In other words, other “shadow” photons (identical photons in split-off branches of the universe) went through the other slit and interfered with the one in our branch. We cannot see those other photons directly (by definition, they are in separate parallel worlds once decoherence happens), but their effects – like interference fringes – are visible. Thus, something real yet unseen is at work. Deutsch emphasizes that these unseen counterparts obey the same physical laws and exert real influence (e.g. causing certain spots on the screen to be dark due to destructive interference). Denying their reality would mean having no explanation for those effects beyond “the math says so.”

By being a realist about the quantum wavefunction, Everett and Deutsch turn what others considered philosophical nonsense into a testable (at least in principle) physical claim: that the universe is constantly branching, and that the schism between branches can be detected under the right conditions. In fact, experiments in quantum computing and interference are increasingly able to indirectly confirm the existence of quantum coherence between what are, in effect, separate “worlds.” These experiments don’t show other worlds like in a sci-fi movie, but they show that quantum states behave exactly as if the alternatives are real and capable of interference. For example, interference patterns disappear if one tries to detect which slit a photon went through; in many-worlds terms, that is because interaction with a detector entangles the photon with the measuring device and the branches “split” (decohere) such that they no longer interact. Many-worlds has no special collapse mechanism – it just says once the branches separate, they cease to interfere. But when they haven’t yet irreversibly separated, interference occurs – a sign that multiple configurations are coexisting for real.

While the Many-Worlds Interpretation is still debated (not all physicists are convinced of its ontological reality), it stands as a bold example of how a realist mindset pushes science forward. It takes quantum theory’s equations seriously as description of reality, and thereby rescues quantum mechanics from mere instrumentalism. Rather than settling for “the calculation gives the right numbers, end of story,” the realist insists on a coherent story of what is actually happening in nature. As Deutsch remarks, calling Many-Worlds an “interpretation” is misleading – it is simply the quantum theory itself taken literally. Competing interpretations often introduce non-realist elements (like a magical collapse or dependence on observers’ knowledge) that leave questions unanswered. By being a realist, one is committed to the idea that nature’s processes are well-defined and objective even when we are not looking – the moon is there when no one observes it, and an electron has a state even if unmeasured. This commitment steers us to find consistent descriptions of those processes (e.g. the branching universe). It also prevents the complacency of saying “since we can never observe other branches, they are not real.” The history of science is rife with things once thought unobservable that later came into view with new techniques. Even if other quantum branches remain forever inaccessible, treating them as real yields a fruitful understanding of why our world behaves as it does. It exemplifies the maxim that assuming reality exists beyond our current reach often guides us to new discoveries – or at least to better understanding of known phenomena.

4. Mind and Consciousness: One might wonder, does realism only apply to the external physical world? What about the mind, consciousness, subjective experience? Interestingly, Deutsch’s realism (and Popper’s fallibilism) apply here too. Some argue consciousness has a mystical, non-physical aspect that might be beyond scientific explanation. Others like Roger Penrose have posited that human minds can perceive mathematical truths that no algorithm could derive, suggesting perhaps the brain taps into non-computable physics or Platonic truth. Deutsch’s stance, however, is that we should be realists about the mind just as we are about anything else – meaning we treat consciousness as a phenomenon arising from physical processes (such as computations in the brain), not as a magic ghost in the machine. He criticizes arguments (like Penrose’s) that elevate the human mind to an infallible oracle of truth. Our thoughts and mathematical insights are also fallible conjectures. We can be wrong even in math (for example, believing a proof is valid when it’s not), so there’s no reason to invoke non-physical processes to explain consciousness. By maintaining a unified reality – with the mental world as part of the physical world – science can approach the problem of consciousness rationally. In practice, this means fields like neuroscience and cognitive science proceed with the assumption that mental states correspond to brain states (even if we don’t yet know how). Again, the realist view spurs investigation: if consciousness is real and grounded in physical law, then understanding the brain’s machinery will eventually shed light on it. The anti-realist or dualist view (that consciousness is beyond physical reality) might lead one to think it’s futile to study brain circuits to understand the mind. Here too, realism proves the more productive and courageous stance – it refuses to put any fundamental aspect of existence behind a veil. If something has real effects (and consciousness surely does, as it affects our actions and communications), the realist scientist will treat it as part of reality to be understood. This attitude has driven research into everything from brain imaging to AI models of cognition. While a final “theory of consciousness” remains elusive (a known unknown), the commitment is that there is a truth of the matter waiting to be discovered.

Why Realism Matters for Truth – and for Us

Science is often described as a search for truth about the universe. Realism is essentially what anchors that search. If one didn’t believe there was an objective truth to find, why search at all? By insisting that there is an objective reality and that our theories can be more or less true about it, realism provides the moral and intellectual motivation for rigorous inquiry. It is, in a sense, a pact of integrity between scientists and nature: we will not be satisfied with pat answers or handy formulas, we will always ask “but is this how things really are?” This restless curiosity is the engine of discovery.

Furthermore, the pursuit of truth under realism has significance beyond laboratories and equations. The user who posed this question hinted at a larger vision: “Truth is the Only Path for Love and Consciousness to prevail.” This poetic assertion underscores that our commitment to reality and truth is intertwined with our deepest human values. How so? Consider consciousness – our ability to reason, to be aware, to seek meaning – it flourishes in an environment where reality is acknowledged, not denied. A mind mired in delusions or falsehood cannot function optimally; we grow as individuals and as a society by facing truths, even uncomfortable ones, and learning from them. Similarly, love – understood broadly as empathy, connection, valuing others – depends on recognizing reality: seeing people as they truly are, understanding real needs and consequences (for example, to love someone effectively, one must understand their reality, not cling to an illusion about them). In a metaphorical sense, commitment to truth is an act of love for what is real – it is honoring the world as it exists rather than as we wish it to be.

In the context of science, many of the advancements that have improved human life (a tangible form of love or benevolence) came from insisting on true understanding of reality. The defeat of diseases, the harnessing of electricity, the creation of the internet – none of these would have been possible if scientists had resigned themselves to superficial appearances or declared deeper inquiry “not worth it.” It was precisely by striving to uncover “eternal, significant, and meaningful truths” that we achieved these things. Each scientific truth, once grasped, becomes eternal in the sense that it remains true and can be built upon; it’s significant in that it empowers us; and it’s meaningful because it enriches our picture of the world and our place in it.

Another aspect to consider is that realism fosters wonder and humility at the same time. It tells us the universe exists in its majestic complexity regardless of our opinions – which is humbling – yet it also tells us we can know it better and better, which is empowering. The more we discover, the more we realize how much remains undiscovered. Realism keeps us from falling into complacency. It’s a reminder that nature can surprise us; there are “unknown unknowns” out there – phenomena we haven’t even conceived of yet – but by being open to reality, we might one day uncover them. This orientation is perfectly captured by Deutsch’s book title The Beginning of Infinity: he argues that with the right approach (critical realism and optimism), human knowledge has no upper bound – an infinite vista of deeper understanding stretches before us. Every time we remove a veil (e.g. discovering the DNA double helix, or seeing the first exoplanet, or detecting gravitational waves), we not only answer a question but often reveal new questions. Realism encourages us to embrace this infinite quest rather than shy away from it. It replaces the fear of the unknown with curiosity and awe.

Finally, realism is linked to accountability in science. If we accept that our theories are saying something about reality, then we must test them rigorously against the facts of reality. This fosters a discipline where theories must explain and predict real observations, not just sound internally coherent or please our biases. In other words, realism enforces an empirical and honest approach: nature is the judge, and we must be willing to let even our most cherished ideas go if experiments disagree. Anti-realism, by contrast, can sometimes provide an escape hatch from that accountability (“the theory is just a convenient device, so if it doesn’t match reality, no matter, it wasn’t a literal claim anyway”). By closing that escape hatch, realism aligns science with truth-seeking in a very practical sense – it demands that we always check our ideas against the way the world truly is, and thus it protects us from self-deception.

Conclusion

In conclusion, to do proper science, you have to be a realist because realism is the commitment that there is a truth to be found and that our theories and inquiries are meaningful attempts to capture that truth. Reality, as independent and sometimes elusive as it may be, is the only arbiter of our scientific claims. History shows that the greatest scientific advances came from peering beyond appearances and believing in a deeper reality: from Newton inferring gravity’s pull across empty space, to Maxwell trusting in invisible fields, to Einstein imagining the warping of spacetime, to modern physicists accepting the bizarre reality of quantum superpositions and multiple worlds. These leaps required a fearless belief that the universe has an intelligible structure that we can progressively discover.

Realism in science is not a naive claim that we already know what is real – it is an attitude of fidelity to whatever the truth may turn out to be. It is saying: “I will not arbitrarily limit what nature can be; I will follow the evidence and the logic of theory wherever it leads, even if that means accepting entities or concepts beyond my immediate perception.” This attitude is essential for science to be a truth-seeking endeavor rather than just a catalog of observations or a set of convenient rules. By being realists, scientists keep alive the spirit of discovery – the drive to explain the seen by invoking the unseen, until the unseen becomes seen (or at least understood). Every time we have made the invisible visible (be it microbes under a microscope, or distant galaxies in a telescope, or quantum particles in a cloud chamber), we have expanded the domain of the real that we comprehend. And each expansion has empowered humanity – intellectually, technologically, and even morally.

David Deutsch’s warning about “bad philosophy” reminds us that we should be wary of any viewpoint that counsels despair about truth or declares the quest for understanding at an end. In science, dogmatic skepticism can be as dangerous as dogmatic certainty – both shut the door on inquiry. The realist walks the challenging middle path: never claiming final certainty but never giving up the search for truth. Such a stance requires both courage and humility: the courage to posit bold explanations and believe in a reality beyond the immediately known, and the humility to accept correction and refine our beliefs as new evidence comes in. This is, ultimately, the path by which our knowledge grows.

To circle back to the larger purpose: the pursuit of reality-based knowledge is not just an intellectual game; it is deeply connected to the human condition. By understanding reality, we empower ourselves to make better decisions, to create technology that improves lives, to appreciate the profound beauty of the cosmos, and to align our values with truth. In a world rife with illusions and misinformation, the scientific realist’s ethos – a commitment to evidence and objective truth – is a beacon. It ensures that love and consciousness, those highest aspects of humanity, are grounded in truth and thereby can prevail. For love that is based on illusion may falter, and consciousness that ignores reality may lead to ruin. But love founded on truth and a consciousness illuminated by reality’s light can endure and uplift.

In the end, insisting that science remain realist is insisting that we do not lie to ourselves, that we do not settle for comfortable falsehoods or cynical relativism. It is a declaration that we will engage with the world as it truly is, to the best of our ability. That engagement has carried us from caves to civilization, from ignorance to insight – and it promises to carry us further still. As long as we remain truth-seekers, acknowledging that reality is out there and striving to understand it, our science will continue to uncover “eternal, significant, and meaningful truths.” And in those truths, we will continue to find the foundation for progress, for wisdom, and for the betterment of life.

References:

• Deutsch, D. & Barnett, C. “There is only one interpretation of quantum mechanics”. IAI News, 14 April 2025. (Interview quote: science as understanding “what there is… not visible but still affects the visible”).
• Wikipedia: “Scientific realism” – defining scientific realism as the view that a mind-independent reality exists and science aims to describe it (including unobservable aspects).
• DBpedia: “Reality” – defining reality as “the sum or aggregate of all that is real or existent… known and unknown.” (Reality includes everything that exists, even if beyond current knowledge).
• Deutsch, D. interview in Nautilus magazine (2015) – on the value of fallibilism: “we’re all alike in our infinite ignorance” and the optimistic implication that truth exists and can be approached through error-correction.
• Historical note on atomism: Mach vs. Planck – “Mach maintained that atoms were no more than theoretical fictions, [whereas] Planck believed they were as real as planets.” (Heilbron 1986, as cited) – illustrating the realist vs anti-realist divide over atoms.
• Deutsch, D. interview (2025) – criticism of 20th-century anti-realist philosophy as “bad philosophy” promoting an agenda of not understanding; “trying to short-circuit arguments… settling into a fixed worldview”.
• Deutsch, D. interview (2025) – “We only ever trust propositions that are strictly false, even though they may contain knowledge.” – highlighting that even our best theories are imperfect, yet progressively refined.
• Wikiquote/References on realism and progress – scientific theories converging towards truth over time, and the importance of unobservable entities being treated as real for explaining phenomena.

AI Reasoning

To Do Proper Science, You Have to Be a Realist

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David Deutsch's explanation of science as unraveling the universe, including unseen elements, sets a profound stage for the discussion. This concept deepens our understanding of reality.

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