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Cohesion Dynamics (CD)

Constructor-Theoretic Lens

For readers familiar with Deutsch/Marletto constructor theory and counterfactual frameworks.

This entry route provides a constructor-theoretic interpretation of Cohesion Dynamics, clarifying how CD supplies substrate mechanism beneath task-possibility constraints.

CD and Constructor Theory: Complementary, Not Competing

Cohesion Dynamics does not replace constructor theory. Instead, CD asks a different question:

  • Constructor Theory asks: What transformations are possible? What tasks can be performed?
  • Cohesion Dynamics asks: What substrate conditions make those transformations possible? How do constructors emerge?

CD provides a substrate-level account that could underpin constructor-theoretic principles.

Key Relationship

Constructor theory describes the laws of physics in terms of which transformations are possible. It doesn’t specify the mechanism by which those transformations occur — that’s not its role.

CD proposes a substrate mechanism from which:

  1. Constructors emerge as stable, repeatable informational structures
  2. Tasks correspond to substrate transformations
  3. Impossibility arises from substrate constraints, not added prohibitions

In this sense, CD is a constructor-compatible substrate theory.

Constructor Emergence in CD

What Are Constructors in CD?

In Cohesion Dynamics, a constructor is:

  • A stable informational structure in the substrate
  • Self-reproducing under substrate evolution
  • Capable of causing repeatable transformations in other structures
  • Unchanged by the transformations it causes

Constructors are not assumed — they emerge when substrate conditions permit.

Conditions for Constructor Emergence

The Constructor Emergence Programme (E1) systematically tested which substrate conditions are necessary for constructors to emerge. Key findings:

  • Not all substrates support constructors — emergence requires specific structural properties
  • Refinement of admissibility constraints increases constructor diversity
  • Tolerance regimes determine which constructor types are viable

These results are documented in:

Tasks and Transformations

Tasks in Substrate Terms

A task in constructor theory is a specified set of possible input/output transformations. In CD, a task corresponds to:

  • A class of substrate state transitions
  • Constrained by coherence and reconciliation rules
  • Performable by a stable structure (constructor)

Possible vs Impossible

Constructor theory distinguishes:

  • Possible tasks — transformations that can be performed
  • Impossible tasks — transformations prohibited by laws of physics

In CD:

  • Possible tasks correspond to substrate transformations consistent with cohesion constraints
  • Impossible tasks are those that would violate substrate coherence or reconciliation rules

Importantly: CD derives impossibility from substrate mechanics, not from additional prohibitions.

Counterfactuals in CD

Constructor theory is fundamentally about counterfactual properties — what would happen under different conditions.

CD provides a substrate framework for counterfactual reasoning:

  • Branching structures in substrate capture counterfactual possibilities
  • Reconciliation constraints determine which counterfactuals are physically instantiated
  • Irreconcilable branches provide a substrate-level interpretation of quantum superposition

This means CD can ground counterfactual statements in substrate structure rather than treating them as primitive.

Information in CD vs Constructor Theory

Both frameworks take information seriously, but in different ways:

Constructor Theory

  • Information is a physical quantity
  • Defined in terms of distinguishability of states
  • Governed by task-possibility constraints

Cohesion Dynamics

  • Information is the substrate content
  • Cohesive structures carry information
  • Information evolves under reconciliation rules

CD’s informational structures could provide the physical realisation of constructor-theoretic information.

Key Papers for Constructor Theory Readers

Primary Reference

R-CCC: Continuum Capability Classification

  • Formal classification of constructor-capable continua
  • Synthesises results from Constructor Emergence Programme (E1)
  • Explains substrate conditions for constructor emergence
  • Start here for constructor-theoretic interpretation

Mechanism Papers

M2: Construction Mechanism

  • Formal definition of construction in substrate terms
  • Fixed-point characterisation of constructors
  • Stability and repeatability conditions

M1: Cohesion Mechanism

  • Reconciliation and closure operations
  • Foundation for understanding constructor stability

Foundational Papers

F-series: Foundational Postulates

  • Ontological commitments of CD
  • What CD assumes vs what it derives

Substrate Definition

A-series: Substrate Mechanics

  • Formal specification of the discrete substrate
  • Network topology, update rules, operational semantics

Quantum Information and Constructors

Constructor theory addresses quantum information using the principles of distinguishability and interoperability. CD provides a substrate interpretation:

Quantum Structure in CD

  • Superposition provides a substrate-level interpretation via irreconcilable branching in substrate
  • Entanglement arises from shared cohesion constraints across branches
  • Measurement can be interpreted as reconciliation-forced branch partition, with outcome selection analysed further in ongoing work (see planned B5)

This is detailed in:

Quantum Constructors

CD predicts that quantum-capable continua require more refined admissibility constraints than classical constructors:

  • Classical constructors emerge under weaker constraints
  • Quantum constructors require stricter coherence regimes
  • No new substrate primitives needed — just refinement of regimes

This represents a potentially testable consequence, explored further in the P-series.

Reading Path for Constructor Theory Readers

  1. R-CCC: Continuum Capability Classification — Constructor emergence classification
  2. M2: Construction Mechanism — Formal construction definition
  3. F-series: Foundational Postulates — Ontological starting points
  4. B-series: Structural Consequences — Quantum structure and branching
  5. A-series: Substrate Mechanics — Full substrate specification

Why This Matters

CD is Not “Just Mechanism”

Some might dismiss CD as “just providing mechanism for constructor theory.” But this misses the point:

  1. Mechanism matters — showing how constructor principles could be realised in substrate is non-trivial
  2. CD makes additional predictions — substrate structure constrains observable physics beyond constructor theory alone
  3. Emergent structure — CD derives which transformations are possible, rather than postulating them

CD Constrains Constructor Theory

If CD is correct, it places additional constraints on constructor-theoretic principles:

  • Not all conceivable tasks are substrate-realisable
  • Constructor emergence is conditional on substrate properties
  • Quantum-like structure is strongly selected under substrate conditions that support reconciliation and interference

These constraints are potentially testable (P-series predictions).

Further Exploration

Contact and Discussion

Interested in discussing the relationship between CD and constructor theory? See Contact for how to reach the author or start a discussion.

Note: This lens emphasises constructor-theoretic interpretation. For order-theoretic perspectives, see Order-Theoretic Lens. For general introduction, see Conceptual Guide.