Damascene Philosophy

QuestionsXXIII

Is science the only path to truth?

Science has been astonishingly successful. Does that make it the only reliable source of knowledge, or only the best tool for some questions?

Reading time
4 min
Difficulty
Intermediate
Branch
Knowledge
First posed
Francis Bacon, 1620; the Vienna Circle, 1920s; Thomas Kuhn, 1962

The question

In 400 years, science has taken us from bloodletting to vaccines, from candles to computers, from guessing at the stars to photographing a black hole. No other way of thinking has produced anything close to this record of predictive and practical success.

This raises a natural thought: if science is so good at finding truth, perhaps it is the only way of finding truth. Whatever cannot be investigated scientifically either is not knowledge or is not real. This view is sometimes called scientism, often by its critics.

But the question has layers. Is mathematics science? It does not use experiments. What about ethics, history, or knowing what it feels like to be in love? And does science itself tell us the truth about unobservable things like electrons and dark matter, or only give us useful models? This last question is the debate over scientific realism.

“Whereof one cannot speak, thereof one must be silent.”

Ludwig Wittgenstein, Tractatus Logico-Philosophicus (1921)

Why it matters

How much authority science has shapes public policy, education and personal decisions. Both overrating and underrating it carry real dangers: dismissing evidence on vaccines or climate on one side, dismissing ethical and humanistic questions as meaningless on the other.

It also bears on philosophy itself. If only science yields knowledge, then philosophy, including this site, is either a branch of science or a waste of time.

Key terms

  • ScientismUsually a critical term for the view that science is the only source of real knowledge, or that every legitimate question is a scientific one.
  • Scientific realismThe view that our best scientific theories are approximately true, including what they say about unobservable things like electrons.
  • FalsifiabilityKarl Popper's criterion for a scientific theory: it must make predictions that could, in principle, turn out false.
  • Paradigm shiftThomas Kuhn's term for a revolution in science in which one framework of theories, methods and assumptions is replaced by another.
  • VerificationismThe view that a statement is meaningful only if it can be verified, at least in principle, by experience, or is true by definition.

The positions

Position I

Science is the only path

All genuine knowledge about the world comes from science, broadly understood as empirical investigation and reasoning about evidence.

Position II

Scientific realism

Mature scientific theories are approximately true, including what they say about unobservable things like electrons and genes.

Position III

Anti-realism and paradigms

Science gives us useful, empirically adequate models, but we need not believe its claims about the unobservable. And what counts as good science changes with paradigms.

Position IV

Many paths to truth

Science is one powerful way of knowing among several. Mathematics, ethics, history and first-person experience yield genuine knowledge too.

Arguments and objections

Science is the only path

Best argument
Science is just careful, systematic, self-correcting inquiry. Where other methods (tradition, revelation, intuition) have conflicted with science, science has almost always won. Alex Rosenberg argues that physics fixes all the facts, and what it cannot capture is not a fact.
Strongest objection
The claim 'only science yields knowledge' is not itself a scientific finding. No experiment could establish it. So by its own standard, it is not knowledge. The logical positivists' verification principle faced exactly this self-refutation problem.
The reply
Defenders often retreat to a broader notion of science that includes logic, mathematics and philosophy done rigorously, which avoids self-refutation but makes the thesis less striking.

Scientific realism

Best argument
The 'no miracles' argument, given by Hilary Putnam: realism is the only philosophy that does not make the success of science a miracle. If electrons did not exist, it would be inexplicable that theories about them predict so precisely and let us build working technology.
Strongest objection
The 'pessimistic meta-induction': many past theories that were very successful, like the ether theory of light and the caloric theory of heat, turned out to be false about their central unobservable entities. By induction, our current theories probably are too.
The reply
Structural realists answer that what survives theory change is the mathematical structure, not the picture of what underlies it, and that we should be realists about structure.

Anti-realism and paradigms

Best argument
Bas van Fraassen's constructive empiricism holds that the aim of science is to save the phenomena: to get the observable consequences right. Thomas Kuhn showed that science proceeds through paradigm shifts, in which the very standards of evidence change. Neither fits the image of steady progress toward truth.
Strongest objection
Science clearly does make progress: later theories predict everything earlier ones did and more. And the line between observable and unobservable seems arbitrary: are things seen through a microscope observed?

Many paths to truth

Best argument
We know that 7 + 5 = 12, that slavery was wrong, and that the Battle of Hastings was fought in 1066, without performing experiments on any of them. We know what pain feels like from the inside in a way no third-person description captures. Science is a refinement of our wider ability to reason, not its replacement.
Strongest objection
Critics worry this opens the door to unchecked claims. If intuition or tradition can count as knowledge, how do we filter out error and wishful thinking?

Who argued what

  • Science is the only path Alex Rosenberg, Rudolf Carnap
  • Scientific realism Hilary Putnam, Richard Boyd, John Worrall
  • Anti-realism and paradigms Bas van Fraassen, Thomas Kuhn
  • Many paths to truth Thomas Nagel, Immanuel Kant, Susan Haack

Where you stand

Do our best scientific theories describe reality?

Choose one to see how people answer.

Variations

The demarcation problem

What separates science from pseudoscience? Popper proposed falsifiability: a scientific theory must make predictions that could turn out false. Astrology and some forms of psychoanalysis, he argued, could explain any outcome, so they told us nothing. Later philosophers found the criterion too simple, but the question it answers remains urgent.

Go deeper

Kuhn's revolutions

In The Structure of Scientific Revolutions (1962), Thomas Kuhn described 'normal science' as puzzle-solving within an accepted framework, or paradigm. Anomalies accumulate until a crisis, and a revolution replaces the old paradigm with a new one, as when Copernican astronomy replaced Ptolemaic, or Einstein's physics replaced Newton's. Kuhn's most controversial claim was that successive paradigms are partly 'incommensurable': they use concepts that cannot be fully translated into each other, making direct comparison difficult.

Schools of thought: Empiricism, Logical positivism, Pragmatism

Related ideas

Question

Why trust that the future will be like the past?

The sun has risen every day of recorded history. Hume asked a question no one has fully answered: what makes that a reason to expect it tomorrow?

Question

How do you know anything at all?

You believe you are reading a screen. Can you rule out every way that belief might be false? If not, do you really know it?

Question

Why is there something it is like to be you?

Science can explain what the brain does. The hard problem asks why any of that doing is accompanied by experience at all.

Question

Is morality objective?

Is 'cruelty is wrong' true the way '2 + 2 = 4' is true? Or is it more like 'chocolate is delicious'?

Question

Are there other versions of you?

On one serious reading of quantum mechanics, every possible outcome happens, each in its own branch of reality, with its own copy of you.

Further reading and sources

Open questions

  • What do you know that no experiment could ever prove?
  • Is the claim 'only science gives knowledge' itself scientific?
  • Will today's best theories look as wrong in 300 years as the ether looks now?

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