Plant Cognition — A Critical Review and APS Interpretation

Framing Note (APS_WEB)

This article reviews the current state of the plant cognition debate and clarifies the APS position. It integrates empirical findings and philosophical critiques to show how plant cognition can be understood as viability-oriented evaluative organisation without invoking anthropomorphism or reducing cognition to mechanism.

1. The Problem: A Conceptually Unstable Debate

Debates over plant cognition have long oscillated between inflation and dismissal. Some researchers attribute to plants forms of intelligence, learning, and memory, citing their complex signalling networks, environmental responsiveness, and adaptive plasticity (Trewavas, 2003; Baluška & Mancuso, 2009; Gagliano et al., 2016). Others reject such claims outright, emphasising the absence of neurons, centralised nervous systems, and representational architectures (Alpi et al., 2007; Taiz et al., 2019).

At stake is not merely terminology, but a deeper conceptual issue. If cognition is equated with neural processing or conscious awareness, plant cognition appears implausible by definition. If it is extended to any adaptive responsiveness, it risks collapsing into a trivial description of biological regulation.

The debate thus reveals a missing middle:

A biologically grounded account of cognition that is neither neural nor trivial.

2. The Case For Plant Cognition

Proponents emphasise a range of well-established empirical features:

  • distributed environmental sensing
  • systemic electrical and hormonal signalling
  • developmental plasticity
  • memory-like modulation (e.g. stress priming)

Recent syntheses highlight the integrated and adaptive nature of plant responsiveness (Segundo-Ortín & Calvo, 2025; Novoplansky, 2024). Some experimental findings suggest forms of habituation or associative learning (Gagliano et al., 2016), reinforcing claims that plants exhibit genuinely cognitive behaviour.

3. The Case Against

Critics argue that such interpretations rely on conceptual overreach.

Their objections are consistent:

  • cognition requires nervous systems
  • cognition requires representation
  • cognition requires consciousness

On this view, plant behaviour—however complex—remains biochemical regulation rather than cognition. Philosophical critiques further warn that extending cognitive language risks undermining its explanatory value (Hansen, 2024; Parise, 2024).

4. Where the Debate Goes Wrong

Both positions rely on unstable assumptions.

  • Proponents risk expanding cognition without clear criteria.
  • Critics restrict cognition to a narrow class of systems.

The result is a conceptual impasse.

Cognition is being defined either too narrowly or too broadly.

What is missing is a biologically grounded framework that specifies when cognitive description is warranted.

5. APS: Cognition as Viability-Oriented Modulation

The APS framework reframes the problem.

Rather than asking whether plants have minds, APS asks whether they exhibit structured, viability-grounded evaluative modulation.

Within APS:

  • life is viability-oriented, constraint-closed organisation
  • agency is the modulation of activity relative to persistence
  • cognition is a structured form of such modulation, integrating activity across scales

Cognition is therefore not tied to neurons or representation, but to the organisation of activity in which differences are evaluated relative to viability.

6. Diagnostic Criteria

APS identifies cognition through organisational criteria rather than analogy.

Three dimensions are central:

Viability grounding
Modulation contributes to the system’s persistence under perturbation.

Normative grounding
Some trajectories are better or worse relative to continued viability.

Cross-scale integration
Local processes are coordinated within whole-system organisation.

7. Plants as Minimally Cognitive Systems

On these criteria, plants qualify as minimally cognitive systems.

They exhibit:

  • viability-grounded responses (e.g. defence, stress regulation)
  • normative asymmetry (successful vs unsuccessful trajectories)
  • cross-scale integration (hormonal, electrical, developmental coordination)

These are not isolated reactions but organised responses to perturbation that sustain the system’s own persistence.

Plants therefore instantiate:

Minimal cognition as viability-oriented evaluative organisation.

8. What Plants Do Not Exhibit

APS sharply limits the scope of this claim.

Plants do not exhibit:

  • representational cognition
  • centralised integrative architectures
  • conscious awareness

This distinction prevents anthropomorphic projection while preserving the biological reality of minimal cognition.

9. Development and Teleology

Recent critiques argue that autonomy-based accounts fail to explain the directed character of biological development (Rama, 2026). Development appears to involve forms of goal-directedness not reducible to immediate self-maintenance.

APS addresses this directly:

Development is not a separate goal beyond viability, but the temporally extended reorganisation of viability-oriented, constraint-closed organisation across scale.

Growth, plasticity, and regeneration are therefore structured forms of persistence, not externally imposed ends.

10. Implications

This reframing has several consequences:

  • cognition becomes a graded biological phenomenon
  • the boundary of cognition shifts from structure to organisation
  • plants serve as a critical test case for non-neural cognition
  • evolutionary continuity is preserved without conceptual inflation

The debate is transformed from a question about mental states to one about organisational structure.

11. Conclusion

The plant cognition debate has remained unstable because cognition itself has been poorly grounded. When tied to consciousness, it excludes plants. When tied to responsiveness, it becomes trivial.

APS resolves this by grounding cognition in viability-oriented organisation.

Plants do not think in an anthropomorphic sense. Nor are they merely reactive systems. They exhibit structured, normatively grounded modulation of activity relative to their own persistence.

Plant cognition is therefore neither illusion nor metaphor, but a minimal, biologically grounded form of evaluative organisation.