How Realism Became Independence: 4 The Rise of Scientific Realism

By the middle of the twentieth century, the Newtonian image of a world composed of objects with intrinsic properties had been shaken by developments in modern physics. Yet the philosophical doctrine that equated realism with ontological independence did not disappear. Instead, it was reformulated and defended with renewed vigour within the philosophy of science.

This defence took shape under the banner of scientific realism.

Scientific realism emerged not primarily from physics itself but from debates within philosophy about how to interpret the success of scientific theories. In responding to sceptical and anti-realist positions, philosophers sought to defend the idea that science genuinely describes the world rather than merely providing useful instruments for prediction.

In doing so, they often inherited the classical conception of reality without examining its historical origins.

The Anti-Realist Challenge

During the early and mid-twentieth century, several influential philosophical movements expressed scepticism about the truth of scientific theories.

Logical positivists argued that theoretical entities—such as electrons or fields—should be understood primarily as components of predictive frameworks rather than as literal descriptions of reality. Later philosophers developed related positions suggesting that science aims not at truth but at empirical adequacy or instrumental usefulness.

These views threatened to undermine the intuitive idea that science reveals how the world actually is.

Scientific realism arose as a response to this challenge.

The Realist Response

Philosophers such as J. J. C. Smart, Hilary Putnam, and Richard Boyd argued that the success of science would be inexplicable if scientific theories were not at least approximately true.

The most influential expression of this idea became known as the No Miracles Argument.

According to this argument, the extraordinary predictive success of modern science would be miraculous if scientific theories were merely convenient instruments. The best explanation for their success is that they capture real features of the world.

In defending realism against anti-realism, these philosophers performed an important intellectual task. They preserved the intuition that scientific inquiry is constrained by a reality that exists independently of our theories.

However, in articulating this defence, realism was increasingly identified with a particular metaphysical picture inherited from classical physics.

The Quiet Inheritance

Scientific realists typically assumed that if theories are approximately true, then the entities and properties they describe must exist independently of observation.

Thus realism became associated with the belief that:

• theoretical entities exist mind-independently

• physical systems possess intrinsic properties

• scientific theories describe an observer-independent world

This interpretation appeared natural because it mirrored the metaphysical image that had dominated classical physics. The Newtonian conception of objects carrying intrinsic attributes remained the implicit model of what realism required.

Yet the identification between realism and intrinsic properties was rarely defended explicitly. It was largely inherited from earlier metaphysical frameworks.

As a result, the debate between realism and anti-realism often proceeded under a shared but unexamined assumption: that to be realist about science was to affirm the existence of a fully determinate world of intrinsic properties existing independently of all observation.

A Narrow Definition of Realism

This historical development had an important consequence. The philosophical defence of realism became tied to the preservation of a specific ontology.

Realism was no longer simply the claim that scientific inquiry is constrained by a real world. It became the claim that the world consists of objects possessing intrinsic, observer-independent properties.

Once this identification was established, any challenge to intrinsic properties appeared to threaten realism itself.

The debate was therefore framed as a stark choice: either accept independence ontology or abandon realism.

The Pressure of Modern Physics

Yet the physics that emerged in the twentieth century did not fit comfortably within this framework.

Quantum theory introduced phenomena—such as contextuality and entanglement—that resist interpretation in terms of intrinsic, observer-independent properties. The classical picture inherited from Newtonian mechanics proved increasingly difficult to reconcile with the formal structure of the theory.

Faced with this tension, philosophers and physicists often attempted to preserve independence ontology by proposing additional interpretative structures: hidden variables, collapse mechanisms, or branching worlds.

These proposals aimed to restore the classical image of intrinsic properties underlying quantum phenomena.

But the persistence of interpretative disagreement revealed a deeper problem.

The metaphysical framework inherited from early modern philosophy and reinforced by classical physics was no longer obviously compatible with the structure of modern theory.

The Stage for Reconsideration

By the late twentieth century, the equation between realism and independence had hardened into philosophical orthodoxy. Yet the developments of modern physics were steadily eroding the foundations on which that orthodoxy rested.

The question that now emerges is whether realism truly requires the metaphysical commitments that scientific realists had inherited from the classical tradition.

To answer that question, we must turn to the theory that most directly challenges the intrinsic-property picture.

Quantum mechanics does not merely complicate the classical worldview.

It exposes the limitations of the ontology that worldview assumed.