Biological Naturalism

In The You On AI Encyclopedia

The position generates immediate objections from multiple directions. Dualists argue that if consciousness is caused by brain processes, it is not genuinely irreducible — it is just a high-level physical phenomenon. Materialists argue that if consciousness has its own causal powers, it is not genuinely physical — Searle has smuggled in a form of dualism. Searle's response is that both objections presuppose a false dichotomy between reduction and dualism. Liquidity is caused by molecular processes but is not reducible to them in any useful sense; we can describe the molecular processes, but we cannot replace the concept of liquidity without losing something. Consciousness, similarly, is caused by neural processes without being eliminable.

The implication for artificial intelligence is that substrate independence cannot be assumed. The claim that any system running the right program will produce consciousness assumes that consciousness is computational — that it is the pattern of processing, not the substrate, that matters. Biological naturalism rejects this. Consciousness is produced by specific causal processes. What those processes are remains an open scientific question. That they involve the specific biological machinery of brains, rather than the formal structure of information processing, is Searle's empirical hypothesis.

Searle was explicit that this does not rule out artificial consciousness in principle. "I have not tried to show that only biologically based systems like our brains can think," he wrote. "I regard this issue as up for grabs." Silicon might, in principle, produce consciousness — but only if the silicon instantiated the right causal processes. The point was not that biology is metaphysically privileged but that formal computation, as currently understood, is not the right kind of process. Running a program is not the same as instantiating the biological or biological-equivalent machinery that produces consciousness.

The position cuts against the computationalist assumption that dominated AI research from the 1950s onward — that mind is to brain as software is to hardware, that the specific implementation doesn't matter, that any Turing-equivalent system running the right algorithm would produce the same mental states. Biological naturalism says: the implementation matters, because consciousness is a biological phenomenon with specific causal properties that not every implementation will have.

Origin

Searle developed biological naturalism across multiple works, most systematically in The Rediscovery of the Mind (1992). The position was designed to carve out space for a realist theory of consciousness that neither eliminated the phenomenon (as behaviorism and eliminative materialism did) nor placed it outside the natural world (as dualism did).

The specific term "biological naturalism" appeared in Searle's work in the 1980s and became the label for his overall philosophical position, encompassing his views on consciousness, intentionality, mental causation, and the relationship between mind and brain.

Key Ideas

Consciousness is real. Subjective experience exists. It is not an illusion, not a convenient fiction, not reducible to behavior or function. There is something it is like to be a conscious being, and that something is a genuine feature of reality.

Consciousness is biological. It is caused by neurobiological processes in the brain, in the same way that digestion is caused by stomach processes. It is a natural phenomenon, not a supernatural one, investigable by science.

Causation without reduction. Lower-level neural processes cause higher-level mental states, but this does not make the mental states eliminable. The analogy: molecular processes cause liquidity, but this does not eliminate liquidity as a useful level of description.

The substrate question is open. Searle did not claim that only biological systems can be conscious. He claimed that formal computation, as currently understood, does not produce consciousness. Some other substrate might, if it instantiated the right causal processes.

The mechanism is unknown. What specific biological processes produce consciousness remains a scientific question. Searle's philosophical position does not answer it; it specifies what kind of answer would be adequate.