Based on the provided sources, particularly the work of Ladyman, Ross, Wiesner, and Vitale, the relationship between hierarchy, non-ergodicity, speciation, causality, and constraint can be untangled by viewing them as interconnected components of structural evolution and complexity.
The short answer is: Non-ergodicity (history) provides the context in which hierarchy (structure) can evolve. Speciation is the mechanism by which this structure differentiates into distinct “Real Patterns.” Constraint is the structural glue that holds the hierarchy together (often mistaken for “downward causation”), while causality is the heuristic we use to track information flow within these constraints in the special sciences.
Here is the detailed breakdown of the relationships:
1. Non-Ergodicity Creates History (The Foundation)
A system is non-ergodic if it does not visit all possible states; it gets “locked in” to specific paths. This is the foundation of complexity.
• The Relationship: Without non-ergodicity, there is no history, only random fluctuations (equilibrium). Non-ergodicity allows for the accumulation of “frozen accidents” (historical events that constrain the future), which generates Logical Depth[1].
• Connection to Speciation: Walport notes that future possibilities are “constrained by the frozen accidents in [a species’] evolutionary past”[3][4]. Evolution is fundamentally non-ergodic; if it were ergodic, species would dissolve back into a soup of random mutations.
2. Hierarchy is the Architecture of Non-Ergodic History
Because the world is non-ergodic, it can build stable structures over time. This leads to hierarchy.
• The Relationship: Herbert Simon’s parable of the watchmaker explains that complex systems must evolve through stable intermediates (sub-systems)[5][6]. This creates a hierarchy (atoms → molecules → cells → organisms).
• Connection to Constraint: Hierarchy is defined by the decoupling of time scales. Interactions at the lower level (micro) are much faster than at the higher level (macro). This separation allows the higher level to act as a stable constraint or boundary condition for the lower level[6][7].
3. Speciation is the Generator of “Real Patterns”
Speciation is the specific process within biological hierarchies that generates distinct “individuals” or “types.”
• The Relationship: In Rainforest Realism, species are “Real Patterns”—they are informationally stable structures that support predictions[8][9]. Speciation is a symmetry-breaking event where a population (a real pattern) splits, creating two new distinct patterns with their own non-ergodic histories[10][11].
• Connection to Hierarchy: Speciation populates the levels of the hierarchy with diverse functional units. Without speciation (differentiation), the hierarchy would be a homogenous lump rather than a diverse ecosystem.
4. Constraint vs. Causality (The Structural Shift)
The sources distinguish sharply between causality (often viewed as a “folk” concept or a heuristic) and constraint (viewed as structural and fundamental).
A. Causality as a Heuristic for Special Sciences
• Russell’s Thesis: Ladyman and Ross cite Bertrand Russell to argue that fundamental physics does not speak of “causes”; it speaks of functional relationships (equations). “Causality” is a “notional-world” concept used in the special sciences (biology, economics) to track information flow in time-asymmetric systems[12].
• Connection to Non-Ergodicity: We use causal language (“The rock broke the window”) because we live in a non-ergodic, low-entropy region of the universe where time has a direction. In a static “block universe” view of physics, there is only structure, not “flowing” causes[15][16].
B. Constraint as Structural Determination
• Inter-level Relations: Instead of “downward causation” (which risks spookiness or dualism), the relationship between levels in a hierarchy is best understood as constraint[17][18].
◦ Bottom-up: Parts determine the possibilities of the whole (constitutive constraint). ◦ Top-down: The whole (environment/structure) constrains the degrees of freedom of the parts[18][19]. • Example: A cell constrains the chemical reactions within it to keep them far from equilibrium. This isn’t a magical “causal force” pushing down; it is a structural constraint (like a wall or a membrane) that limits what the parts can do[19][20].
Summary of the Web of Relations
| Concept | Role in the System | Relationship to Others |
|---|---|---|
| Non-Ergodicity | The Engine | Prevents the system from dissolving into randomness; allows History to matter[1]. |
| Hierarchy | The Structure | The result of non-ergodic accumulation of stable intermediates; creates levels of scale[5][6]. |
| Speciation | The Process | The branching mechanism that creates distinct Real Patterns (species) within the hierarchy[9]. |
| Constraint | The Glue | The structural relationship between levels. Higher levels constrain the phase space of lower levels[18]. |
| Causality | The Map | The user-interface (heuristic) we use to track flows of influence within the Special Sciences, made possible by non-ergodicity[14]. |
**Final Untangling:**We perceive causality in the world (e.g., predators causing prey to flee) because we are observing real patterns (created by speciation and maintained by hierarchy) interacting in a non-ergodic environment. However, scientifically, these interactions are better described as the evolution of a system under constraints—where the higher levels of the hierarchy (the flock, the market, the species) constrain the probabilities of the lower-level components (the bird, the trader, the organism)[21][22].
References
[1] Ladyman 2012 - What is a complex system.pdf [3] Walport - What can we know about that which we cannot even imagine.pdf [4] Walport - What can we know about that which we cannot even imagine.pdf [5] Ladyman - What is a Complex System.pdf [6] Ladyman 2012 - What is a complex system.pdf [7] [Book] Ladyman - What Is a Complex System.pdf [8] Ladyman - What is a Complex System.pdf [9] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [10] Ladyman 2012 - What is a complex system.pdf [11] Naturalism and the Metaphysics of Emergence.pdf [12] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [14] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [15] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [16] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [17] Naturalism and the Metaphysics of Emergence.pdf [18] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [19] [Book] Ladyman - What Is a Complex System.pdf [20] [Book] Vitale - Logics of Emergence Relational Philosophy.pdf [21] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf [22] [Book] Ladyman - Every Thing Must Go Metaphysics Naturalized.pdf