The Appeal of Universal Sentience
It is increasingly common to encounter claims that all living systems are sentient. Bacteria are said to feel, plants to experience, and cells to possess a primitive form of awareness.
These claims are rarely arbitrary. They are typically motivated by an important insight:
Life is continuous. The difference between simple and complex organisms is one of degree, not kind.
This insight is correct — and necessary. However, it does not follow that all features observed in complex organisms must be present, in even minimal form, in simpler ones.
The challenge is to preserve continuity without collapsing distinct organisational phenomena into one another.
Where the Confusion Arises
The idea that all life is sentient usually arises from a sequence of reasonable steps:
- living systems regulate their internal conditions
- regulation involves sensitivity to environmental differences
- sensitivity involves evaluation relative to persistence
- evaluation appears to imply experience
The first three steps are correct. The fourth is not.
APS identifies the problem as a category collapse: the conflation of constraint-closed regulation, normative evaluation, and subjective experience.
Living systems do not merely react; they evaluate conditions relative to their continued viability. But evaluation, in this sense, does not require subjective experience.
APS’s Core Distinction: Organisation vs Experience
APS does not begin with mind. It begins with life.
More precisely, it begins with viability-oriented, constraint-closed biological organisation — the condition under which a system maintains and regenerates the constraints that sustain its own persistence.
From this organisational condition follows normativity:
- some states are better than others for the system
- the system must act to maintain those states
- failure results in loss of viability
This establishes evaluation as an objective feature of living systems.
But it does not establish experience.
APS therefore separates three levels that are often conflated:
- Agency — viability-oriented activity through which a system sustains its own persistence
- Cognition — the evaluation of environmental differences relative to viability
- Experience (sentience/consciousness) — a further, empirically contingent feature of some systems
This separation preserves continuity while preventing conceptual collapse.
Why Not All Life Is Sentient
The claim that all life is sentient typically rests on the assumption that any form of evaluation must involve experience.
APS rejects this assumption.
A system can:
- differentiate between conditions
- respond selectively
- and reorganise its activity relative to its own persistence
without there being any evidence that these processes are accompanied by subjective experience.
To attribute sentience in all such cases is to extend the concept beyond its evidential basis.
APS therefore adopts a conservative position:
Sentience is not required for biological agency, cognition, or purpose.
It may emerge in systems with particular forms of biological organisation, but it is not a defining feature of life as such.
Continuity Without Inflation
APS fully accepts that life forms a continuous spectrum.
There is no sharp boundary between:
- simple and complex organisms
- minimal and elaborate forms of cognition
- basic and advanced regulatory systems
However, continuity does not imply uniformity.
Different organisational features emerge at different levels of complexity. Treating all of them as present everywhere risks flattening the distinctions that make biological explanation possible.
APS preserves continuity by grounding all life in:
- viability-oriented - biological organisation
- constraint closure
- intrinsic normativity
while allowing additional features — such as sentience‚¬to emerge only where supported by specific organisational structures.
Why the “All Life Is Sentient” Claim Persists
The persistence of this claim reflects a genuine pressure within biology.
Mechanistic language alone struggles to capture:
- the evaluative nature of living systems
- their orientation toward persistence
- and their active regulation of conditions
In response, some accounts expand the notion of sentience to cover all such phenomena.
APS offers a different solution.
Rather than expanding sentience, it clarifies the underlying biological organisation:
- evaluation becomes normativity
- regulation becomes cognition
- persistence becomes purpose
This preserves explanatory clarity without introducing unnecessary psychological commitments.
The APS Position
APS affirms:
- all living systems are agential
- all living systems are normatively organised
- all living systems exhibit cognition as the evaluation of environmental differences relative to viability
That is, all living systems are organised as viability-oriented, constraint-closed systems whose continued existence depends on their own activity.
APS does not affirm:
- that all living systems are sentient
- that evaluation implies experience
- or that consciousness is a universal property of life
Sentience remains:
- an open empirical question
- associated with specific organisational thresholds
- and not required for biological explanation at the level of life itself
APS does not treat sentience as a ubiquitous or minimally present property of all living systems, but as a distinct organisational development requiring independent empirical support.
The Payoff: Precision Without Reduction
By distinguishing biological organisation from experience, APS achieves three things:
- it preserves the continuity between life and mind without collapsing them
- it avoids anthropomorphism without retreating into purely mechanistic description
- it keeps biological explanation grounded in observable organisational features
This allows biology to remain both rigorous and honest about the nature of living systems.
Key Point
Not all life is sentient. All life is agential: sentience, where it occurs, is a further organisational development grounded in, but not constitutive of, viability-oriented biological organisation.