Starrett’s Radical Panpsychism

Mathematician John Starrett’s Radical Panpsychism (RP) is a mathematically grounded philosophical framework for understanding consciousness, which proposes that experience is a fundamental and ubiquitous aspect of reality, not limited to complex organisms but present in all entities. In RP, an entity is a locus of interaction with time-varying properties (degrees of freedom, or DOF) whose dynamical coupling with the DOF of its environment constitutes its experience (Starrett, 2025).

Degrees of Freedom

Mathematically, entities are modeled as fuzzy subsets of spacetime whose DOF are expressed as temporal fibers—attached spaces in which each DOF can be represented. At the atomic level, these DOF are quantum: the shape of an atom’s electron cloud is determined by orbital angular momentum and interactions with electromagnetic and electrostatic fields, the atom’s fuzzy position and velocity, and the spins of its electrons. Mathematically, these states are points in Hilbert spaces: complex two-space for spin and the space of square integrable functions in three-space for the spatial wavefunction, for instance.

In humans, these DOF include all manner of parameters; for example, the position and velocity of our limbs, blood pressure, the distribution of excitations in the rods and cones of our eyes, the flow of electrical impulses in our brains, and the complex suite of sensory patterns that arise, such as when chocolate melts on the tongue. Mathematically, such DOF may be represented in classical phase spaces for limb motion, functional spaces of receptor activations for vision, state spaces of membrane potentials and ion concentrations for neural activity, and high-dimensional manifolds of combined sensory patterns.

From Individuals to Composites

Because each entity’s experience is expressed through the structured evolution of its DOF, the challenge is to explain how multiple entities can together form a higher-order entity with its own unified experience, which is well-known as the ‘combination problem’ in panpsychism. Starrett’s Radical Panpsychism addresses this by introducing the notions of engulfing and co-engulfing, which describe how entities may incorporate or mutually embed one another while preserving the stability of their direct models. In this view, composite experience arises through the reconfiguration of DOF into new patterns of organization rather than through simple aggregation. Entities are never fully sealed off from their environments but remain entangled through persistent interactions, so boundaries are graded rather than sharp. This gradedness allows composite structures to form dynamically without severing their continuity with the environment.

Structural Grammar and Direct Model

In Starrett’s view, our mentality, simply stated, is our structure, and our structure is an expression of our environment. Every entity has a different structural grammar—the kinds of things its degrees of freedom can express. Its experience, expressed as the evolving spectrum of its DOF, is constrained by this grammar. This ongoing pattern is called the direct model: not a mathematical abstraction, but the direct expression of an entity’s coupling with its environment. Through this lens, the forms of experience can be arranged along a spectrum, from the simple variation of quantum DOF to the richly integrated patterns of human consciousness.

The RP framework, Starrett argues, also highlights the role of surrogate models, internally generated representations that stand in for features of the environment or the self. These surrogate layers cushion raw interactions, integrating them into coherent patterns that manifest as qualia. In this way, Radical Panpsychism links the simplicity of atomic responsiveness to the layered self-modeling of organisms, offering a scale-relational account of consciousness without invoking nonphysical primitives.

Hierarchy of Degrees of Freedom

As structural complexity increases, so does the diversity and hierarchy of internal DOF. Higher-level DOF are scaffolded on lower-level ones: molecular vibrations arise from atomic motion; neural signaling builds on electrochemical gradients; and linguistic behavior depends on the coordination of motor, auditory, and conceptual subsystems.

Each organizational layer inherits and reconfigures the dynamics beneath it. In molecules, DOF include vibrational, rotational, and translational modes. In bacteria, relevant DOF may include chemical concentrations, ion gradients, or ciliary orientation. In multicellular organisms, higher-order DOF emerge: visual features, limb articulations, and symbolic communication. Each such structure contributes to the evolving direct model, expressing the configuration of the experiential set in the language of the entity’s own dynamics.

Starrett claims that Radical Panpsychism reframes the hard problem of consciousness. Instead of asking how subjective experience could possibly arise from physical processes, RP takes experience to be the structured evolution of physical degrees of freedom themselves. On this view, qualia are not mysterious additions to matter but the felt aspect of an entity’s direct model, shaped and layered by surrogate structures. What remains “hard” is not the existence of experience but the scientific and mathematical task of mapping how structural grammars at different scales give rise to the richness of human consciousness. RP thus shifts the hard problem from metaphysical speculation to the concrete challenge of characterizing the dynamics of experience across levels of organization.

Radical Panpsychism seeks to integrate physicalist science and panpsychist intuition into a single framework. By grounding experience in the structural dynamics of entities across scales, it provides a unified account of consciousness that extends from fundamental particles to human cognition. In this vision, mentality is continuous with the physical world: our structures, and thus our minds, are direct expressions of our environments (Starrett, 2025).