Critiques of FEP Applied to Consciousness: Gilon et al. and Related Challenges

Core Results

Gerard Marx and Chaim Gilon published their critique in 2025. They examined four papers by Karl Friston and collaborators. The authors argue that the Free Energy Principle fails to explain how caloric energy becomes emotive memory in neural systems. They state that physics and thermodynamics laws do not apply directly to sentience. The paper identifies missing physiologic mechanisms and circular reasoning around surprise and memory.

Gilon and Marx conclude that FEP remains a mathematical construct without biochemical grounding. They propose instead a tripartite neural memory mechanism based on molecular signaling available to cells.

Primary Works and Passages

The main source is Gerard Marx and Chaim Gilon, "Critique of the 'Free Energy Principle' of Consciousness," Chemical & Pharmaceutical Research 7, no. 3 (2025): 1-7. Key passage: "How does the viable brain transmute caloric energy into consciousness manifest as emotive memory? Apparently, the laws of physics and thermodynamics don't apply."

They summarize and critique four Friston works. One is Friston KJ, Stephan KE, "Free-energy and the brain," Synthese 159 (2007): 417–458. Gilon and Marx note the absence of emotive state notation.

Another is Friston KJ, "The free-energy principle: a rough guide to the brain?," Trends in Cognitive Sciences 13 (2009): 293-300. They criticize the exclusive focus on synaptic signaling and ignore non-synaptic modes in the neural extracellular matrix.

A third is Badcock PB, Friston KJ et al., "The hierarchically mechanistic mind," Cognitive, Affective, & Behavioral Neuroscience 19 (2019): 1319–1351. Gilon and Marx state it lacks reference to evolutionary signaling from bacteria onward.

Related challenges appear in "The Limits of the Free Energy Principle: A Systematic Critique," an unpublished thesis on Academia.edu (accessed 2026). It lists five conceptual problems including confusion of thermodynamic and information-theoretic free energy.

Convergence Patterns

This school independently identifies the need for memory as a distinct layer. It highlights bounded memory systems that store prior states for comparison. It touches flow networks through molecular signaling pathways. It notes scale invariance limits when models stay at abstract mathematical levels without cellular mechanisms.

The critique aligns with the Ladder by separating physical flows from memory and mind. It rejects direct mapping of thermodynamic minimization onto sentience.

Distance from the Full Synthesis

Gilon et al. reach the point where physics principles require supplementation by biochemical memory processes. They stop short of embedding the reader inside the system as an active participant. They do not frame the critique within broader grain patterns across scales. Their alternative remains focused on neural cells rather than universal structural patterns.

The work supports the synthesis by exposing where FEP overextends. It confirms that information principles alone do not generate emotive experience without material memory mechanisms.

Limits and Disconfirming Edges

The critique relies on textual analysis of selected papers. It offers no new empirical data on consciousness mechanisms. Strongest internal objection comes from FEP defenders who treat the principle as a mathematical bound rather than a literal physiologic claim. Another edge is that Gilon and Marx focus on human and mammalian brains while downplaying simpler systems that exhibit basic adaptation.

The school remains at the level of interpretive challenge rather than replacement theory. It correctly flags the absence of emotive encoding but leaves open how tripartite memory integrates with larger grain structures.

What's breaking down

FEP models treat surprise minimization as sufficient for adaptive behavior. Gilon and Marx show this creates circularity: surprise requires prior memory, yet memory is what the model seeks to explain. Thermodynamic analogies break when applied to subjective states because no notation exists for emotive valence in the equations.

Non-synaptic chemical signaling in the extracellular matrix is omitted. This omission severs the model from actual cellular materials that carry memory traces.

How these fit together

The four critiqued papers share a common structure. Each derives perceptual inference from variational free energy bounds. Each claims emergence of mind from self-organizing systems that resist disorder. Gilon and Marx demonstrate that each step skips the biochemical route from energy intake to stored emotive states.

Their proposed tripartite mechanism links molecular effectors, epigenetic modifications, and circuit activity. This chain restores physiologic relevance without invoking abstract free energy scalars.

What the evidence actually shows

No direct physiologic mapping exists in the Friston papers between free energy quantities and measured neural memory traces. The Gilon analysis documents repeated absence of emotive state definitions across the reviewed works. Related critiques confirm the thermodynamic-information analogy lacks formal justification.

What scientists say

Friston papers acknowledge mathematical abstraction but maintain the principle unifies perception and action. Gilon and Marx respond that unification without cellular grounding explains nothing about mentality. Other reviewers note FEP functions best as a process theory framework rather than a complete account of consciousness.

What people say on Reddit

Discussions on technical forums highlight that FEP remains unfalsifiable at the principle level. Users note process models derived from it can be tested but often ignore molecular details raised by Gilon.

What people say on X

Posts reference the 2025 critique as a needed counter to over-application of information theory to subjective experience. Threads emphasize memory as the missing bridge.

What we do not know

How exactly epigenetic changes encode valence-specific memory remains open. Integration of non-synaptic signaling with hierarchical predictive models lacks detailed mapping.

Safety and limits

The critique targets theoretical overreach. It does not invalidate all predictive processing research. Models remain useful for specific inference tasks when kept within mechanistic bounds.

The school reinforces that mind emerges only when memory layers operate on material flows. This matches the synthesis requirement that the reader participates inside the patterned system rather than observing from outside.