第五章_能动性分级

Chapter 5 Levels of Agency: From Plants to Humans

In living systems, there are clear hierarchical differences in agency.

However, this hierarchy is not a matter of "superiority versus inferiority," but rather of structural transitions. The difference at each level is not a quantitative change, but a structural qualitative leap.

Level 1: Sessile Life (Example: Plants)

Being "unable to move" does not mean a lack of agency, but rather that there is no large-scale movement on a spatial position scale.

Yet, plants possess:

Regulation of growth direction (phototropism, gravitropism)
Perception of chemical signals (sensing nutrients and threats in the environment)
Environmental modification (e.g., altering the soil microenvironment, releasing chemical substances)
Regulation of reproductive strategies (adjusting flowering and fruiting based on environmental conditions)

They possess agency, but structurally, this agency is:

Lack of a nervous system
Distributed (decision-making is dispersed throughout the plant body)
Primarily chemically regulated (hormones, signaling molecules)

Level 2: Lower Animals

Structural transition point: The emergence of the nervous system.

Emergence of the nervous system
Formation of sensory-motor loops

Agency is manifested as:

Locomotion (active displacement)
Foraging
Evading
Simple learning and conditioned reflexes

This is a qualitative leap from "distributed chemical regulation" to "centralized electrical signal processing."

Level 3: Higher Animals

Structural transition point: The complexification of brain structure.

Stratification of brain structure (forebrain, midbrain, hindbrain)
Enhanced memory systems (structures such as the hippocampus)
Emotional regulation participating in behavioral decision-making (limbic system)

Level 4: Humans

Structural transition point: The expansion of the prefrontal cortex.

A qualitative leap occurs here:

Advanced agency of tool creation and use

This is not only an intellectual legacy of Marxism but also a fact mutually recognized by modern evolutionary theory and cognitive science: