Cognition as Signal Dynamics

A proposal toward a protocol theory of cognition.

Contents

1. Introduction
2. The Physical Continuity of Cognition
3. Local Causality and the Perspective of Physical Systems
4. Signals as Primitive Ontology
5. The Cognitive Protocol
6. Organization and Emergence
7. Toward a Protocol Theory of Cognition

Introduction

Every mature scientific discipline begins by identifying the primitive entities from which its subject matter may be described. Classical mechanics begins with bodies, forces, and motion. Electromagnetism describes fields, charges, and their interactions. Thermodynamics concerns itself with energy, entropy, and state variables. Each theory establishes a minimal vocabulary from which richer phenomena may later be explained.

The study of cognition has historically proceeded in the opposite direction. Rather than beginning with the simplest physical principles, it often begins with concepts already belonging to sophisticated cognitive systems: representation, information, memory, reasoning, knowledge, beliefs, symbols, intentions, language, or consciousness. These concepts undoubtedly describe genuine regularities, but they also risk becoming explanatory primitives before their own physical origins have been established.

This essay adopts a different approach. Its objective is not to explain every observable property of cognition, nor to replace neuroscience, psychology, computer science, or artificial intelligence. Instead, it asks a more fundamental question:

What is the smallest physical ontology capable of supporting every possible manifestation of cognition?

The answer sought here must remain independent of implementation. Whether a cognitive system is realized by biological neurons, electronic circuits, chemical networks, optical media, quantum substrates, or physical architectures not yet imagined should be irrelevant. A satisfactory physical foundation ought to remain valid regardless of the material from which cognition is constructed.

The position developed throughout this essay is intentionally minimalist. Cognition is regarded as neither a special substance nor an exception to physical law. It introduces no new forces, no privileged forms of matter, and no non-physical principles. Instead, cognition is proposed to be a particular organization of the same lawful causal processes through which every physical system evolves.

The universe already possesses mechanisms through which physical systems influence one another. If cognition is genuinely a physical phenomenon, then it must arise from those same mechanisms rather than from an additional category of causation. The task, therefore, is not to invent a new ontology specifically for minds, but to identify which aspects of ordinary physical interaction become organized into cognitive processes.

The central thesis of this essay is that cognition is most fundamentally understood as organized signal dynamics. Every cognitive system continuously receives propagating physical influences, undergoes lawful state transformations, and produces further propagating influences. Higher-order concepts—including memory, representation, meaning, reasoning, and knowledge—are not rejected, but regarded as emergent organizations of these more primitive dynamics rather than their foundations.

The goal is therefore not reduction for its own sake. Rather, it is to establish an ontology sufficiently minimal that every cognitive phenomenon may, in principle, emerge without requiring additional fundamental entities beyond those already present within the causal structure of the physical universe.

Part 1. The Physical Continuity of Cognition

Modern science has repeatedly advanced by discovering continuity where earlier thought perceived discontinuity. The motions of celestial bodies and falling stones were once regarded as fundamentally different phenomena until both were recognized as consequences of the same gravitational laws. Electricity and magnetism, once separate domains, became unified within a single theoretical framework. Heat ceased to be viewed as a distinct substance and became understood as the statistical behavior of microscopic physical systems.

Each of these developments replaced special explanation with more general principles. The exceptional became ordinary—not by diminishing its complexity, but by revealing its deeper continuity with the rest of nature.

Cognition presents a similar challenge.

Human experience naturally encourages the intuition that thought occupies a special position within the universe. We experience perception, imagination, memory, planning, and reasoning from the inside. These phenomena appear so rich and distinctive that they invite the conclusion that cognition itself must possess equally distinctive physical foundations.

Yet every empirical investigation of cognition points in the opposite direction. Damage to physical structures alters cognition. Chemical changes alter cognition. Electrical activity accompanies cognition. Development modifies cognition. Evolution shapes cognition. Artificial systems increasingly reproduce isolated cognitive abilities using entirely different physical substrates. Nothing presently known suggests that cognition requires an exception to ordinary physical law.

If cognition is indeed wholly physical, then it should not require a unique ontology separate from the ontology already describing the physical universe. Instead, cognition should emerge from the same causal principles governing every other physical process. The question is therefore not whether cognition obeys physics, but which physical abstractions best capture the processes from which cognition arises.

This shift in perspective has important consequences.

Rather than beginning with minds, one begins with physical systems. Rather than beginning with thoughts, one begins with interactions. Rather than beginning with meaning, one begins with causality.

Only after those foundations have been established does it become meaningful to ask how increasingly sophisticated cognitive phenomena emerge.

This ordering is not merely philosophical preference. It reflects the structure of scientific explanation itself. Explanatory concepts should arise from simpler principles whenever possible. They should not appear among the primitives unless no further reduction can be achieved.

For this reason, concepts such as memory, representation, information, knowledge, and reasoning will intentionally be absent from the initial ontology developed throughout this essay. Their absence should not be mistaken for a denial of their existence. Rather, it reflects the hypothesis that these are higher-order organizations whose physical basis remains describable using a smaller collection of more fundamental concepts.

The challenge, then, is to identify those concepts.

Whatever ontology is selected must satisfy several requirements.

• It must apply equally to biological and artificial systems.
• It must remain independent of any particular material substrate.
• It must describe cognition as an ordinary physical phenomenon.
• It must permit increasingly sophisticated forms of organization without introducing new physical principles.
• It should explain not merely existing cognitive systems, but any physically possible cognitive system.

These requirements substantially constrain the search. They suggest that the appropriate primitives are unlikely to resemble familiar psychological concepts. Instead, they should belong to the more general language of physical causality itself.

Part 2. Local Causality and the Perspective of Physical Systems

Any physical theory of cognition must begin with a simple observation that is so fundamental it is easily overlooked: no physical system possesses direct access to the universe.

Every physical system exists only within its own local state. Whatever occurs elsewhere can influence that system only through physical processes connecting the two. Nothing acts instantaneously across arbitrary distance. Every interaction requires a causal chain through which influence propagates across space and time.

Modern physics expresses this principle in many different forms. Electromagnetic influences propagate as electromagnetic fields. Mechanical disturbances propagate through materials. Chemical influences propagate through diffusion and molecular transport. Gravitational influences possess finite causal structure. Even where the mathematical descriptions differ, the physical principle remains remarkably consistent: interactions are local, lawful, and mediated by propagating physical processes.

This observation has profound consequences for cognition.

A brain never encounters the external world directly. Photons reflected from an object interact with retinal cells. Pressure waves displace structures within the ear. Chemical molecules bind to receptors. Mechanical forces stimulate touch-sensitive tissues. Every sensory experience begins not with external objects themselves, but with physical disturbances arriving at the organism.

The same principle applies beyond biology.

An electronic sensor detects changing voltages. A radar system receives reflected electromagnetic waves. A robotic manipulator measures forces acting upon its joints. A bacterium responds to chemical gradients. A thermostat responds to thermal changes.

Although these systems differ enormously in sophistication, they share an important limitation: none possesses privileged access to reality itself. Each encounters only those physical influences that successfully propagate to it.

The converse is equally important.

No physical system acts directly upon the universe either. Every action it performs likewise consists of physical influences propagating outward into other systems. Muscles generate forces. Loudspeakers generate pressure waves. Transmitters emit electromagnetic radiation. Chemical organisms release molecules. Every outward effect becomes another propagating physical influence.

Consequently, from the perspective of any individual physical system, the universe consists not of objects encountered directly, but of continual streams of incoming and outgoing causal influence.

Incoming physical influences
↓
Internal physical state
↓
Outgoing physical influences

This simple observation is more than a convenient diagram. It establishes the minimal interface through which every physical system participates in the causal structure of the universe.

The universe may contain fields, particles, quantum states, spacetime geometry, or structures still unknown to physics. None of this alters the immediate perspective of an individual physical system. Whatever ultimately exists, influence arrives only through physical propagation and departs through physical propagation.

The distinction is subtle but essential.

This essay does not claim that the universe is literally composed of signals. Physics already provides its own ontology for matter, fields, and spacetime. Instead, it adopts a more modest position:

For every physical system, all causal interaction with the rest of the universe occurs through propagating physical influence.

If cognition is itself a physical phenomenon, then cognition cannot escape this constraint. Whatever cognition may ultimately be, it necessarily unfolds within this continual exchange of propagating causal influence.

The next question therefore becomes unavoidable.

If every cognitive process ultimately consists of physical systems responding to propagating causal influence, what is the most appropriate abstraction for those influences themselves?

Part 3. Signals as Primitive Ontology

The previous discussion establishes an important constraint upon any physical theory of cognition. Every cognitive system exists as a local physical system embedded within a larger causal universe. It neither observes reality directly nor acts upon reality directly. Every interaction with its surroundings is mediated by propagating physical influence.

The question therefore becomes one of abstraction.

Physics possesses multiple ontological vocabularies. One may describe the universe in terms of particles, fields, wavefunctions, spacetime geometry, energy, momentum, or other constructs appropriate to particular physical theories. Each vocabulary successfully captures different aspects of physical reality, yet none appears uniquely suited to describing cognition across every possible substrate.

A cognitive theory seeking maximal generality therefore requires a different kind of primitive. Rather than describing what physical systems are made of, it should describe how physical systems influence one another. The objective is not to replace the ontology of physics, but to identify the smallest abstraction common to every causal interaction upon which cognition depends.

This essay adopts the concept of the signal as that abstraction.

A signal is defined here as a propagating physical disturbance capable of modifying the state of another physical system through lawful interaction. The physical substrate is intentionally left unspecified. A signal may consist of an electromagnetic wave, a pressure wave, a chemical gradient, an electrical potential, a propagating deformation within a material, or any other physical process that carries causal influence from one system to another.

The definition deliberately avoids semantic language. A signal is not information. It is not meaning. It is not a message. It is not a symbol. It is not knowledge.

Those concepts belong to richer descriptions that may eventually emerge from organized collections of signals. At the ontological level developed here, a signal possesses only one essential property: it is capable of participating in causal interaction.

This distinction is fundamental.

Human language encourages us to think of signals as carriers of information. When a person sends a text message, broadcasts a radio transmission, or speaks a sentence, the signal appears merely to transport some underlying content. Within the present framework, this ordering is reversed.

The signal is primary. The content, if any exists, is secondary.

Consider a beam of light leaving a distant star. Whether that light eventually reaches empty space, strikes a telescope, illuminates a planet, or enters the retina of an observer does not alter the physical nature of the propagating disturbance itself. The signal exists independently of whether any observer ultimately attributes meaning to it. Meaning arises only within particular organizations of interacting physical systems.

Likewise, an electrical impulse propagating along a biological axon does not intrinsically represent a color, a memory, or a thought. It is simply a lawful physical event. Only within the enormously complex organization of an entire nervous system may such signals participate in structures that observers later describe as perception or memory.

The same observation applies equally to artificial systems. Electrical transitions inside a processor possess no intrinsic semantics. Semantics emerge only because the broader organization of the system gives those transitions stable functional roles.

By treating signals themselves as primitive, the framework avoids introducing higher-level concepts prematurely. Signals require neither interpretation nor representation in order to exist. They require only physical propagation and lawful interaction.

One might reasonably ask why signals should be preferred over the more general concept of causality itself.

The answer lies in locality. Causality describes an abstract relationship between events. Signals describe the concrete physical mechanisms through which that relationship becomes realized. Because cognition necessarily unfolds within local physical systems, the intermediate propagation of causal influence cannot be ignored. Signals are therefore not intended as replacements for causality, but as its physically realized expression within interacting systems.

Another possible objection concerns systems exhibiting static interactions rather than obvious propagating disturbances. A magnet continuously attracts a piece of iron. A mass continually contributes to a gravitational field. A compressed spring exerts persistent force.

Yet even these examples remain compatible with the present abstraction. The important feature is not whether the interaction appears dynamic to human intuition, but that every change in one system influences another through lawful physical mechanisms constrained by space and time. The signal abstraction is therefore intended to encompass every physical propagation of causal influence, whether transient, continuous, oscillatory, discrete, or otherwise.

Signals should therefore be understood neither as an additional substance nor as a competing physical ontology. They are an abstraction over the countless physical mechanisms through which systems exchange causal influence.

From the perspective of cognition, this level of abstraction is precisely what is required. Whether a future cognitive system communicates through neurons, photons, molecular reactions, superconducting circuits, quantum excitations, or physical media not yet discovered becomes largely irrelevant. Each remains, fundamentally, a system whose evolution depends upon the continual propagation and transformation of signals.

At this level, remarkably little is required.

There exist physical systems. Those systems possess physical state. Signals propagate between them. Incoming signals modify physical state. Modified physical state gives rise to further signals.

Nothing more has yet been assumed. There are no representations. No memories. No beliefs. No symbols. No computations. No intelligence. No consciousness. Only lawful physical systems exchanging propagating causal influence.

The significance of this minimal ontology lies not in what it contains, but in what it intentionally omits. Every omitted concept becomes something to explain rather than something taken for granted.

Part 4. The Cognitive Protocol

Once signals have been adopted as the primitive abstraction, cognition itself can be reconsidered from an entirely different perspective.

Traditional descriptions frequently characterize cognition in terms of what is being processed. Perception processes sensory information. Memory stores information. Reasoning manipulates knowledge. Language communicates meaning. Although useful at higher levels of analysis, these descriptions already assume the existence of semantic entities whose physical origin remains unexplained.

The present framework instead shifts attention away from content and toward the lawful organization governing physical interaction.

The central concept is that of a protocol.

The term is borrowed deliberately from communication theory, although its use here is considerably broader.

A communication protocol does not concern itself with the semantic content of messages. A network packet may contain a scientific paper, an image, encrypted data, random binary values, or no meaningful payload whatsoever. None of these possibilities alters the protocol itself.

The protocol specifies only the lawful constraints governing interaction. It determines how signals are generated, how they propagate, how receiving systems respond to them, and how subsequent signals are produced.

Content is contingent. Protocol is structural.

This distinction is far more general than digital communication. It applies equally to every physical system capable of responding to incoming signals.

Consider a biological neuron. An action potential arrives at a synapse. Electrochemical processes alter the membrane state. If sufficient conditions are satisfied, another action potential propagates along the axon. Nowhere within this description need one invoke beliefs, memories, representations, or meanings. The neuron participates only in lawful signal transformation determined by its present physical state.

The same description applies, at an appropriate level of abstraction, to artificial systems. Voltage transitions alter transistor states. Those altered states influence subsequent transitions. The organization differs enormously from biology, yet the underlying principle remains remarkably similar: incoming signals modify physical state, and physical state constrains future signals.

The protocol therefore consists of the lawful relationships governing four elements:

• the generation of signals,
• the propagation of signals,
• the transformation of physical state by incoming signals, and
• the production of future signals from that transformed state.

Importantly, the protocol is not an external algorithm imposed upon matter. It is the organization of the physical system itself. The laws of physics determine what transformations are possible, while the particular structure of the system determines which transformations actually occur.

Seen in this way, cognition is not fundamentally a sequence of computations in the traditional sense. Computation is one possible realization of organized signal dynamics, but it is not the primitive phenomenon. The more general principle is lawful transformation itself.

This distinction becomes increasingly important when considering physical systems unlike modern computers. Chemical organisms, immune systems, developmental biology, ecological networks, and future cognitive architectures may exhibit sophisticated adaptive behavior without naturally fitting the classical model of symbolic computation. Yet all remain describable as systems whose physical organization constrains the continual transformation of signals.

The protocol therefore occupies a level of description more general than computation while remaining entirely physical.

Notice what has quietly occurred. Nothing in the ontology has changed. No new primitive entities have been introduced. The protocol is not an additional object existing alongside signals. Rather, it is the lawful organization according to which signals and physical state continually determine one another.

At this stage, cognition still has not appeared. There are only organized physical systems participating in continual cycles of signal propagation and state transformation.

The remaining question is therefore the most important one.

How can the extraordinary richness of cognition emerge from nothing more than organized signal dynamics?

Part 5. Organization and Emergence

The ontology developed thus far is intentionally austere. Physical systems exchange propagating signals. Incoming signals modify physical state. Physical state determines future signals according to lawful organization. No additional entities have been introduced.

At first glance, this framework appears almost too minimal to account for the richness of cognition. Human thought involves memory, imagination, planning, abstraction, language, mathematical reasoning, scientific discovery, and conscious reflection. How could phenomena of such apparent sophistication arise from principles so simple?

This question reflects a familiar intuition: that complexity requires equally complex foundations.

The history of science repeatedly suggests otherwise.

The intricate branching of a snowflake emerges from simple physical laws governing crystallization. Planetary systems arise from gravity acting over vast timescales. Biological evolution produces extraordinary diversity through variation, inheritance, and selection. Across many domains of science, remarkably rich structures emerge not because the underlying rules explicitly contain them, but because repeated interaction allows increasingly elaborate organizations to develop.

The present framework proposes that cognition belongs to this broader class of emergent phenomena.

Nothing in the primitive ontology explicitly mentions memory, prediction, reasoning, concepts, or representation. The claim is not that these phenomena are illusory, but that they are organizational properties rather than ontological primitives.

This distinction is essential.

An ontological primitive cannot be explained within the theory that assumes it. An emergent property can.

If representation is treated as primitive, one may describe cognitive systems that manipulate representations, but one has not explained why representations exist in the first place. Likewise, if memory is assumed from the outset, the question of how physical systems become capable of memory has merely been postponed.

A successful physical theory should reverse this relationship. Rather than assuming sophisticated cognitive concepts, it should demonstrate how they arise from more elementary dynamics.

This is precisely why the ontology introduced in the previous sections is so minimal. Every omitted concept becomes something the theory must eventually account for.

Emergence, however, should not be misunderstood.

To say that a property emerges is not to say that it is unreal or merely a matter of human convenience. Emergent phenomena possess genuine causal regularities. Temperature is not fundamental in the ontology of particle physics, yet it remains an objective physical property. Fluid turbulence is not written into the equations governing individual molecules, yet it exhibits predictable structure. Biological evolution is not encoded into the laws of chemistry, yet it is an entirely real consequence of those laws operating over time.

Likewise, memory, representation, and reasoning may emerge as stable organizations of signal dynamics without requiring independent ontological status.

Organization as the Source of Cognitive Difference

A natural objection now presents itself.

If every physical system exchanges signals and undergoes lawful state transformations, does the present framework imply that every physical system is cognitive?

The answer depends upon what is meant by cognition.

At the most fundamental level, every physical system participates in the same causal fabric. A rock, a hurricane, a bacterium, a neuron, and a human brain all exist within the continual propagation of physical influence. None escapes the universal dynamics described by the preceding sections.

Yet participation alone does not constitute cognition.

The crucial distinction lies not in the existence of signals, but in the organization of their transformation.

A stone resting on the ground responds to external influences according to its material properties. The transformations that occur are lawful, but relatively simple. A thermostat possesses a richer organization capable of maintaining a target temperature through feedback. A bacterium responds to chemical gradients while maintaining its internal structure. A nervous system integrates signals across billions of interacting cells whose collective dynamics extend across multiple temporal and spatial scales.

These systems differ enormously, yet the difference is not one of fundamental physics. They differ in the architecture of their signal dynamics.

Several characteristics become increasingly prominent as this organization grows more sophisticated.

• Persistence across time.
• Integration of signals arriving from many sources.
• Feedback in which present activity influences future activity.
• Adaptation through changing internal organization.
• Recursion in which the products of previous transformations become inputs to later transformations.
• The formation of stable dynamical structures that survive many cycles of interaction.

None of these characteristics requires additional physical principles. Each describes increasingly elaborate organizations of the same underlying protocol.

Cognition therefore appears not as a binary property suddenly possessed by some systems and absent from others, but as a continuum of organizational richness. The transition from simple reactive systems to sophisticated cognitive systems is analogous to the transition from isolated molecules to living organisms. The difference lies in organization rather than ontology.

The Emergence of Internal Structure

As signal transformations become increasingly interconnected, they begin to produce structures that persist beyond the signals that originally generated them.

A transient disturbance may modify physical state in such a way that future signals are altered long after the original disturbance has disappeared. From the outside, such persistence may be described as memory.

Likewise, collections of recurring signal transformations may become sufficiently stable that they reliably participate in future interactions. Observers may eventually identify these stable organizations as concepts, categories, or representations.

Importantly, these descriptions belong to the observer rather than to the primitive ontology.

Nothing within the protocol labels one persistent pattern as a memory and another as a belief. Those distinctions arise because certain organizations exhibit reliable functional behavior across many interactions. Human observers develop vocabulary to describe these regularities in much the same way that physics develops vocabulary for waves, vortices, crystals, or galaxies.

The ontology itself remains unchanged.

Signals propagate. Physical state evolves. Organization becomes increasingly elaborate. Higher-order regularities emerge.

The explanatory direction is always upward, never downward. Meaning does not create signal dynamics. Signal dynamics give rise to the organizations within which meaning eventually becomes possible.

The Game of Life and Ontological Economy

Perhaps the clearest illustration of emergence without additional ontology is provided by Conway's Game of Life.

The Game of Life consists of an extremely simple universe. Each cell occupies one of two states, and every update depends only upon the states of neighboring cells according to a small collection of local rules. Nothing within these rules mentions gliders, oscillators, spaceships, breeders, logic gates, or self-replicating structures.

Yet such structures undeniably emerge.

Observers eventually recognize recurring configurations because those configurations exhibit remarkable stability or interesting behavior. Entire mathematical theories have been developed to classify these emergent patterns. None of those classifications, however, alters the underlying ontology.

The rules never identify a glider. The universe never distinguishes a logic gate from any other arrangement of cells. Only the dynamics exist. Everything else is an emergent description of recurring organization.

This distinction is more profound than it first appears.

One could imagine attempting to explain the Game of Life by introducing new primitive entities whenever increasingly complex structures were discovered. Gliders could become fundamental objects. Oscillators could receive their own special laws. Spaceships might require additional ontological categories.

Such a theory would rapidly become unmanageable while explaining remarkably little.

The elegance of the Game of Life arises precisely because none of these additions is necessary. A tiny collection of local rules suffices to generate arbitrarily rich organization.

The present framework proposes that cognition should be approached in much the same spirit.

Rather than elevating memories, symbols, representations, concepts, or meanings to primitive status, the theory seeks an ontology capable of generating them through organization alone.

This is not reductionism in the pejorative sense of denying higher-level phenomena. On the contrary, it is an affirmation that higher-level phenomena deserve explanation rather than assumption.

The richer the organization becomes, the richer the vocabulary required to describe it. Psychology, neuroscience, linguistics, and artificial intelligence therefore remain indispensable. They describe organizational regimes whose complexity would be invisible if one considered only primitive signal dynamics.

What changes is not the legitimacy of these higher-level descriptions, but their place within the explanatory hierarchy.

They are no longer the foundation. They become the consequences.

The remaining task is therefore to assemble the preceding ideas into a unified view of cognition itself.

Part 6. Toward a Protocol Theory of Cognition

The preceding sections have progressively reduced cognition to an increasingly small collection of physical principles. The reduction has been intentional. Every concept introduced has been examined according to a single criterion: whether it must be assumed from the outset or whether it can emerge from something more fundamental.

The resulting ontology is remarkably sparse.

• Physical systems exist.
• Physical systems possess state.
• Systems influence one another through propagating signals.
• Incoming signals modify physical state.
• Physical state constrains the generation of future signals.

Everything else follows from organization.

This claim should not be mistaken for incompleteness. Minimal scientific theories often appear almost trivial until one appreciates the consequences of their repeated application. Newton's laws consist of only a handful of principles, yet they describe the motion of planets, projectiles, pendulums, and tides. Maxwell's equations occupy only a few lines, yet they explain radio, optics, electricity, magnetism, and electromagnetic radiation across the universe.

Simplicity at the level of foundations does not imply simplicity at the level of behavior.

The protocol proposed throughout this essay should therefore be understood as a candidate foundation rather than a complete theory of cognition. It does not attempt to explain every observable cognitive phenomenon directly. Instead, it attempts to identify the smallest physical vocabulary from which every cognitive phenomenon may, in principle, be derived.

This distinction has important implications.

Traditional cognitive theories frequently begin with information, computation, representation, or symbolic manipulation. These concepts have proven enormously useful, particularly within neuroscience, cognitive science, and artificial intelligence. Yet they also presuppose forms of organization already capable of supporting such abstractions.

The present framework reverses the explanatory direction.

Information is not primitive. Computation is not primitive. Representation is not primitive. Meaning is not primitive.

Instead, each is viewed as a stable organizational property arising within sufficiently rich networks of signal transformation.

This shift is subtle but profound.

Consider computation. Modern computer science naturally describes digital systems in terms of algorithms manipulating symbolic values. At that level of abstraction, this description is entirely appropriate. Yet beneath every algorithm lies a physical system whose organization governs the propagation of electrical signals. Transistors do not execute algorithms because they understand computation. Rather, algorithms emerge because engineers have organized signal dynamics into stable physical structures whose collective behavior admits computational interpretation.

The same reasoning extends beyond digital computers. Biological nervous systems perform no symbolic manipulations in the literal sense. Individual neurons neither store concepts nor evaluate propositions. They participate in electrochemical interactions whose collective organization gives rise to increasingly sophisticated patterns of behavior.

From this perspective, computation itself becomes one possible regime of organized signal dynamics rather than the universal substrate from which all cognition must be understood.

The protocol therefore occupies a level of abstraction beneath computation while remaining entirely compatible with computational descriptions whenever such descriptions prove useful.

The Observer and the System

An important distinction has quietly appeared throughout the preceding discussion.

The physical system and the external observer do not necessarily employ the same ontology.

The observer may legitimately describe a nervous system as containing memories, beliefs, representations, goals, concepts, predictions, or intentions because these descriptions capture stable regularities exhibited by the system's behavior.

The physical system itself possesses no such vocabulary.

Its evolution consists only of continually changing physical state produced by lawful interactions with propagating signals. The observer's conceptual framework compresses this enormous complexity into higher-level descriptions whose predictive value justifies their use.

This relationship mirrors many other scientific domains. Meteorologists speak of storms. Biologists speak of organisms. Economists speak of markets. Physicists speak of waves. None of these descriptions appears explicitly within the underlying microscopic equations. They emerge because observers identify recurring organizations that remain stable across many interactions.

Likewise, cognitive vocabulary represents an observer's language for describing persistent organizations of signal dynamics.

This does not diminish its legitimacy. On the contrary, it explains why multiple descriptive levels can coexist without contradiction.

A neuroscientist, a psychologist, and a physicist may all describe the same cognitive process using entirely different conceptual frameworks. Each framework captures genuine regularities appropriate to its own scale of observation. The protocol theory proposed here concerns only the lowest level required to support all higher descriptions.

Why This Framework Matters

The value of a minimal ontology is not aesthetic simplicity alone. It provides a common language capable of describing cognitive systems regardless of their implementation.

A biological brain, an artificial neural network, an adaptive chemical system, or a cognitive architecture yet to be invented may differ radically in material composition while sharing the same underlying organizational principles. Each receives signals, undergoes lawful state transformation, and produces further signals according to its physical organization.

By locating cognition at this level of abstraction, the theory avoids binding itself to any particular technology or biological mechanism.

Future discoveries may completely transform neuroscience. Artificial intelligence may adopt physical substrates unlike contemporary electronics. Physics itself may refine its understanding of matter, fields, or spacetime. None of these developments necessarily invalidate the protocol theory so long as physical systems continue to interact through lawful propagation of causal influence.

In this sense, signals are not proposed as the substance from which the universe is constructed. They are proposed as the most general description of how any physical system participates in the universe's ongoing causal evolution.

The Universe as Continuous Signal Dynamics

Stepping back from cognition reveals a broader perspective.

The universe is not a collection of isolated objects occasionally interacting. It is a continuously evolving network of causal relationships extending across space and time. Every physical system exists because it continually exchanges influence with other systems. Every structure persists only because its internal organization maintains itself through ongoing physical interaction.

Stars radiate energy. Planets exchange gravitational influence. Atmospheres transport momentum. Cells regulate chemical gradients. Brains exchange electrochemical signals. Civilizations communicate across technological networks.

These phenomena differ enormously in scale, composition, and complexity, yet each participates in the same universal fabric of propagating causal influence.

Cognition is therefore not an exception to the universe's operation. It is one of its most sophisticated organizational achievements.

The distinction between a brain and a star is not that one obeys fundamentally different physical principles. Both participate in the same causal universe. What differs is the extraordinary architecture through which their internal signal dynamics unfold.

As organization increases, new forms of stability become possible. Persistent internal state gives rise to memory. Adaptive organization gives rise to learning. Recursive transformation gives rise to planning. Stable internal models give rise to representation. Coordinated symbolic dynamics give rise to language. Each stage emerges from the previous without requiring additional ontological categories.

The protocol remains unchanged. Only the organization becomes richer.

Conclusion

This essay began with a simple question:

What is the smallest physical ontology capable of supporting cognition?

Rather than beginning with minds, meanings, representations, or information, it began with ordinary physical systems participating in the causal structure of the universe.

Every physical system exists only through local interaction with its surroundings. Every influence arrives through propagating physical disturbance. Every action likewise propagates outward through lawful physical processes. Whatever cognition may ultimately be, it cannot escape these constraints.

Signals were therefore introduced not as a replacement for the ontology of physics, but as the minimal abstraction describing the propagation of causal influence between physical systems.

From this perspective, cognition becomes neither mysterious nor exceptional. A cognitive system is a physical system whose organization transforms incoming signals into outgoing signals through continually evolving internal state. The protocol governing these transformations constitutes the physical foundation of cognition.

Everything commonly associated with intelligent behavior—memory, learning, representation, prediction, reasoning, language, and knowledge—is understood as emergent organization rather than primitive ontology.

This framework deliberately leaves many important questions unanswered. How do stable internal representations emerge? How should learning be characterized within signal dynamics? Can information itself be derived rather than assumed? How does consciousness relate to organized protocol dynamics? What mathematical structures best describe the protocol?

These questions remain open because they belong to the theory built upon the foundation rather than to the foundation itself.

A successful scientific theory often begins not by explaining everything, but by identifying the smallest set of principles from which everything else may be explained.

The proposal developed here is that cognition admits precisely such a foundation.

The universe already possesses lawful mechanisms through which physical systems exchange causal influence. Cognition does not require additional ontological categories beyond those mechanisms. It is the natural consequence of their organization.

Seen in this light, a cognitive system is not separate from the physical universe. It is one way in which the universe organizes its own causal dynamics into persistent, adaptive, increasingly self-referential structures capable of participating in the ongoing transformation of future signal dynamics.

A protocol theory of cognition therefore begins neither with thought nor with meaning. It begins with the universal language already spoken by every physical system: the continual propagation and lawful transformation of signals.