Are Simpler Explanations Always Better?

There is an idea that appears across science, math, and philosophy: simple explanations often seem to work better than complicated ones. This idea is usually called Occam’s Razor, which says that when two explanations fit the same facts, we should prefer the simpler one. Scientists use it when choosing between theories. Mathematicians use it when deciding which proof feels the most satisfying. Even everyday reasoning relies on it when we choose the explanation that requires fewer assumptions.

But why does this principle work so well? Does the universe really favor simplicity, or is simplicity only a habit of human thinking?

Why Do Simple Theories Work?

Occam’s Razor was first written about by medieval philosopher William of Ockham. He believed that explanations should not multiply entities without necessity. In modern terms, a theory should only include what it needs to make correct predictions. If two theories both match the data, the simpler one usually generalizes better.

In physics, this idea shows up everywhere. Newton’s laws describe motion using just a few equations, yet they predict the motion of planets, falling objects, and tides. Maxwell’s equations describe all classical electromagnetism with elegant structure. Even Einstein’s insight that gravity is a curvature of spacetime came from searching for the simplest laws consistent with observation.

Simplicity works because it tends to avoid overfitting. A complicated explanation can match every detail, including random noise. A simpler explanation ignores the noise and captures the stable pattern underneath. In this sense, a simple theory is strong not because it leaves things out, but because it focuses on what stays the same.

Fluid dynamics simulation showing a passive scalar flowing around an obstacle. The entire pattern is produced by a small set of differential equations that govern motion in fluids. Here, simple physical laws can generate highly complex behavior, which is one reason scientists often view simplicity as a sign of deeper structure in nature.
"A Jupyter sandbox environment coupled into the high-order Navier-Stokes solver Xcompact3d", Felipe N. Schuch, F.D. Vianna, A. Mombach, J.H. Silvestrini, October 2020, https://www.fschuch.com/en/publication/2020-jupytercon/

When Simplicity Fights Against Reality

Even though simple theories are powerful, there are moments when reality pushes back. The philosopher Nelson Goodman argued that simplicity depends on what language we use. A rule that looks simple in one vocabulary may look complex in another. For example, the statement “all emeralds are green” is simple, but so is “all emeralds are grue,” where grue means green until a certain date and blue afterward. Both rules fit all observed emeralds, so why do we prefer one over the other? Goodman’s point is that simplicity itself is not fixed. It depends on how we describe the world.

In science, simplicity sometimes fails because nature is genuinely messy. Weather systems shift with small changes in temperature. Turbulence in fluids refuses to fit a neat formula. Some biological systems behave chaotically even when their initial conditions are almost identical. These cases show that simplicity has limits. It is not a law of nature, but a guiding principle that helps us navigate patterns that happen to be orderly.

Some philosophers, like Elliott Sober, argue that simplicity is not a guarantee of truth. It is a useful tool for building theories, but the universe has no obligation to follow it. The world might be simple in some areas and wildly complex in others.

Does Simplicity Reveal the Nature of the Universe?

One idea proposed by philosophers like David Deutsch is that the universe has simple laws because those laws must support stable predictions. A universe governed by highly complicated rules might not allow any stable regularities at all. In that kind of world, science would not be possible. We could not form concepts like mass or charge if the rules changed constantly. So perhaps only universes with simple foundations allow beings like us to exist.

Another view says that simplicity is a feature of how the human mind works. We prefer neat theories because we evolved to detect patterns that help us survive. The mind looks for simple rules because simple rules are easier to remember, communicate, and use. This view suggests the universe may not be simple at all. We may just be biased toward explanations that match our cognitive limits.

Both possibilities are interesting. Either the universe is simple enough for minds like ours to understand, or our minds lean toward simplicity because they were shaped by a world with consistent patterns.

So, Are Simpler Explanations Better?

Simplicity is a powerful guide. It helps us build theories that generalize, avoid mistakes, and highlight the core structure of things. But simplicity is not a guarantee of truth. It is a tool shaped by how the world behaves and by how our minds interpret it.

Maybe the universe contains both simplicity and complexity. Laws might be simple, while the outcomes that flow from them are intricate. Or maybe our simplest explanations are only temporary steps toward richer theories that capture more detail without losing clarity.

Either way, our search for simplicity reveals something important. It shows how humans try to find order in a universe that often surprises us. And in that search, simplicity continues to be a guide, a hope, and sometimes even an illusion worth exploring.