Subscribe ▶️ YouTube @philosop-HER

The Realism v. Antirealism Debate

Gig Φ Philosophy: Published April, 2026

The Debate

Should we actually believe that the unobservable entities described in our scientific theories exist?

We hear about things like dark energy, quarks, and the Higgs Boson all the time. But nobody has ever seen them with the naked eye. This brings us to a massive philosophical crossroads: the debate between Scientific Realism and Antirealism.

🧠 Food for Thought

So, is science uncovering the deep, hidden blueprints of the universe, or is it simply constructing highly effective models that help us navigate the observable world? The next time you hear about a new discovery in particle physics or cosmology, ask yourself: are we discovering reality, or just inventing a really good map?

Philosophy of Science (COMPLETE - COURSE)

FREE PRIMARY READINGS

Cartwright "Do the Laws of Physics State the Facts?"

Maxwell "The Ontological Status of Theoretical Explanations"

"Commentary - Realism vs. Antirealism"

Radu Dudau "The Realism/Antirealism Debate in the Philosophy of Science"

🔭 The Realist Stance & The "Miracle" Argument

Realists take the view that the account of the natural world offered by science is true, and the entities it postulates really do exist. They concede that past theories have been proven false, but argue that as science progresses, our theories are getting closer to an objective truth.

A major point for the realist camp is Hilary Putnam’s "Ultimate Argument" (often called the "miracle" argument). Putnam argues that realism is the only philosophy that doesn't make the massive success of science a complete miracle. If our theories weren't literally true, and terms like "electrons" didn't refer to real things, how could science possibly be so incredibly successful at predicting the world?

🛠️ Antirealism & Instrumentalism

On the flip side, we have Empiricism (tracing back to thinkers like Hume and Locke), which argues that knowledge is derived purely from sense experience. Because past scientific theories have so frequently been disproven, empiricists maintain a healthy skepticism about unobservable entities.

One popular flavor of antirealism is Instrumentalism. Instrumentalists argue that we should treat things like x-rays, quarks, and dark matter not as real objects, but merely as useful placeholders for mathematical calculations. They are just convenient devices that help us predict results, not actual features of reality.

🦠 The "Crobes" & The Unobservable Line

Can we really draw a hard line between what is observable and what isn't? Grover Maxwell argued forcefully against this dichotomy. He asked us to imagine a fictional scientist who posits the existence of unobservable "crobes" that cause disease. Later, the microscope is invented, and suddenly the "crobes" are perfectly observable.

Maxwell points out that looking through a microscope is just looking through a medium. We wouldn't say rain isn't real just because we are observing it through a windowpane. Maxwell argues there is a continuous transition from looking through air, to eyeglasses, to a microscope. Therefore, drawing a hard line between "observable" and "unobservable" is purely a contingent feature of human physiology and current technology, completely devoid of any real ontological significance.

🏗️ Constructive Empiricism: Saving the Phenomena

Bas van Fraassen (who I actually had the incredible opportunity to study under during my time at San Francisco State!) offers a totally different, antirealist alternative: Constructive Empiricism.

Instead of aiming for literal truth, van Fraassen argues that science aims to give us theories that are simply "empirically adequate".

A theory is empirically adequate when it "saves the phenomena" (meaning everything it says about observable objects and events is true).
Accepting a theory does NOT mean you believe it is universally true; it just means you believe it is empirically adequate.
We can take the language of science literally without committing to the belief that the unobservable entities are real. We just remain agnostic about them.

But what about Putnam's "miracle" argument? Van Fraassen counters it with a Darwinian explanation: the success of science isn't a miracle, it's just natural selection. Theories that aren't empirically adequate simply die out, and the ones we have left are the survivors.