Reductionist Emergence x Constraint-Based Emergence

I was reading Existential Physics: A Scientist's Guide to Life's Biggest Questions by Sabine Hossenfelder...

This is her view on emerging phenomena:
In summary, according to the best current evidence, the world is reductionist: the behavior of large composite objects derives from the behavior of their constituents, but we have no idea why the laws of nature are that way. Why is it that the details from short distances do not matter over long distances? Why doesn’t the behavior of protons and neutrons inside atoms matter for the orbits of planets? How come what quarks and gluons do inside protons doesn’t affect the efficiency of drugs? Physicists have a name for this disconnect—the decoupling of scales—but no explanation. Maybe there isn’t one. The world has to be some way and not another, and so we will always be left with unanswered why questions. Or maybe this particular why question tells us we’re missing an overarching principle that connects the different layers.

So I asked the Copilot: How can the ideas of Terrence Deacon about constraints and absence in some way to be used to counter the reductionism proposed by Sabine?

Here is the interesting conversation that resulted:

Terrence Deacon’s ideas—particularly his concept of constraints as constitutive absences—offer a compelling philosophical counterpoint to the reductionism described by Sabine Hossenfelder. While Sabine emphasizes the decoupling of scales and the mystery of why micro-level details don’t always influence macro-level phenomena, Deacon flips the script by suggesting that what’s absent—not just what’s present—plays a fundamental role in shaping reality.

Let’s unpack how Deacon’s framework could challenge or complement Sabine’s reductionist view:

Deacon’s Core Idea: Constraints as Absence
Constraint ≠ Substance: Deacon argues that constraints are not things but absences—restrictions on possibilities. For example, a river’s path is constrained not just by the water’s properties but by the absence of rock in certain places.

Emergence via Constraint: Higher-order phenomena (like life, mind, or meaning) emerge not merely from constituent parts but from the constraints that shape their interactions. These constraints are not reducible to the parts themselves.

Constitutive Absence: This is the idea that something can be defined by what is not there—what could have happened but didn’t. This absence is real and causally potent.

Countering Reductionism with Constraint-Based Emergence
Sabine’s reductionism says: “Big things behave the way they do because of the behavior of small things.” But Deacon would say:

It’s not just the parts—it’s the pattern of exclusions: The behavior of large systems is shaped by constraints that emerge at higher levels and are not reducible to the micro-level constituents.

Constraints decouple scales: The reason quarks don’t affect drug efficiency or planetary orbits isn’t mysterious—it’s because constraints at each level filter out irrelevant micro-level details. These constraints are emergent and context-dependent.

Absence as explanation: Where Sabine sees a lack of explanation for decoupling, Deacon sees a principle: absence—the structured lack of certain possibilities—is what allows systems to behave independently across scales.