Godfrey-Smith’s Naturalist, Gradualist, Diversified Evolution of Consciousness

Philosopher Peter Godfrey-Smith presents a theory of consciousness that is biologically naturalist and evolutionary gradualist, treating it as an evolved form of subjectivity that developed in diverse ways across animal life. Subjective experience is not an all-or-nothing trait but a graded phenomenon that emerged gradually over deep geological time. He argues that consciousness arose from the basic biological need for an organism to sense its environment and coordinate a response, making it a feature of life that is likely far more widespread and far more varied than commonly assumed.

Godfrey-Smith focuses on subjectivity for two reasons: “First, subjectivity and the associated notion of ‘point of view’ are helpful in defusing arguments against materialism. Second, subjectivity is an explicable evolutionary product.” He calls as evidence “a series of events in the history of life that bear on the origins of subjective experience”—a historical–comparative narrative across early nervous systems, motor control, and self-monitoring of action—arguing that understanding how subjectivity could have arisen in nature might help to narrow the “explanatory gap” between mind and matter (Godfrey-Smith, 2019).

Gradualism and the Evolution of Subjectivity

Godfrey-Smith’s central claim is that subjective experience, or consciousness, arose gradually, not by a sharp demarcation or step-function event. He rejects “threshold models” that demand an on/off criterion, and he defends a graded, multidimensional picture. “In a gradualist approach, we aim not to give an account of which features suffice to make you an experiencing subject, but an account of how some organisms have internal goings-on that are more experiential.” Moreover, “What evolved is not the same thing repeatedly, but something more divergent in kind” (Godfrey-Smith, 2018).

Demanding highly specific, biologically anchored mechanisms and building on gradualism, Godfrey-Smith develops the view that what we call experience in humans is a cluster of traits with different evolutionary histories; some are basic, others later-arriving (report, reflective thought, temporal organization). He distinguishes two interacting experiential strands: sensory/discriminative organization (rich perception, integration of cues) and evaluative/affective organization (valenced moods, appraisals). “A sharp divergence between sensory and evaluative complexity,” he says, “seems possible in principle.”

Comparative Evidence and the Octopus as Alien Mind

He uses invertebrate data (cephalopods, crustaceans, insects, gastropods) to argue that these dimensions can come separately, cautioning against single-criterion litmus tests (Godfrey-Smith, 2018). Indeed, his seminal work with cephalopods, particularly the octopus, as evolution’s “independent experiments” provides comparative insight: cephalopods, he emphasizes, are a radically different form of mind, providing us with disparate datapoints with which to assess consciousness. The evolutionary line leading to octopuses diverged from the line leading to vertebrates (including humans) over 600 million years ago. This makes the octopus an example of a separate, independent evolution of a complex nervous system and sophisticated intelligence. By studying them, we can see which features of the mind are universal and which are incidental products of our own specific evolutionary history (Godfrey-Smith, 2016).

The octopus's unique biology, especially its distributed nervous system (with a majority of its neurons located in its arms), challenges our brain-centric view of consciousness. Its arms can seemingly think and act semi-independently, suggesting a different kind of mind-body integration and perhaps a different structure of subjective experience. “If we can make contact with cephalopods as sentient beings, it is not because of a shared history, not because of kinship, but because evolution built minds twice over… This is probably the closest we will come to meeting an intelligent alien.” More generally, he states, “The mind evolved in the sea. Water made it possible. All the early stages took place in water” (Godfrey-Smith, 2016).

Godfrey-Smith’s project is to explore “experientialization as an evolutionary process” by sketching “one of the hard parts of the gradualist evolutionary story, the part that goes from no to yes, regarding the presence of experience.” He opts for “a view of early nervous system evolution that puts considerable emphasis on the formation and coordination of action itself,” and he considers the transition to “new relationships between sensing and acting, especially in the handling of reafference, the effects of action on the actor's own senses.” In other words, he highlights reafference—the system’s registering its own movements to interpret incoming signals—to explain how a subject-centered perspective could arise. “Once this kind of neural organization is present, it amounts to a processing of what is sensed in a way organized round a tracking of self versus other” (Godfrey-Smith, 2020).

Godfrey-Smith’s sentience framework “is not one in which some inner light waits to come on. The story is not, or need not be, one where that thing, subjective experience, emerges by stages into view.” He says that a series of other things could gradually arise and come together to yield the state we find at the end: consciousness. While “something like movement towards an outcome of experience makes sense,” he stresses that “this need not happen along a single line.” He points out, “There are organisms with sensorimotor arcs that are simpler and not neurally organized, organisms with neural patterns of activity that are mostly coordinative rather than organized around subjectivity, and also organisms with combinations that are more like ours. The goings-on inside various other organisms can be ‘more or less experiential,’ but to say that is not to posit an overall scale. The situation is not one where a cluster of biological features is put together in a combination and the output is a degree of sentience – 0.6, 0.2 – or even an ordering – flowering plants lower than anemones, higher than sponges. Instead, the situation is one where an organism has its own collection of experience-relevant features.”

Thus, consciousness is rooted in the sensing–acting ecology of animals; reafference enables a self/other demarcation that grounds a point of view. As he puts it, “If materialism is true, subjective or felt experience must also have arisen gradually,” and “Subjective experience exists in a graded way… not a single scale from more to less conscious” (Godfrey-Smith, 2020).

Godfrey-Smith engages with other theories of consciousness. While he is sympathetic to “integration” as important, he is critical of theories that detach it from animal life, especially Integrated Information Theory. “Their theory, where integration has no essential connection to sensing, action, and so on, is not the only way to develop the idea.” He recommends linking integration to the “business of being an animal—to acting and sensing” (Godfrey-Smith, 2020).

Embodiment, Biopsychism, and Darwinian Grey Areas

Godfrey-Smith's theory of consciousness is embodied and enactive. This means the mind is not entirely in the brain; rather, it arises from the dynamic interaction between an organism's entire body and its environment. The “self” emerges from the biological imperative to distinguish the body from the non-body and to maintain its integrity against the outside world. Consciousness, then, is the ongoing process of managing this body-world relationship. It is the lived perspective of a body actively navigating its surroundings. This view rejects computational models of the mind that treat the brain as hardware and thought as software, instead emphasizing the inseparable link between life, body, world, and experience.

Regarding biopsychism, the idea that minimal subjective experience might extend to all living things (given minimal cognition and metabolism), he is cautious, advising against easy inferences from minimal cognition to sentience; any extension below neural animals must be argued carefully, with functional roles tied to an organism’s projects (Godfrey-Smith, 2020). While cautious about biopsychism, he is decided against panpsychism (Godfrey-Smith, 2019).

Overall, using the evolution of animal life as a guide for understanding the origins and nature of the mind, Godfrey-Smith says that in a Darwinian context, one should expect a lot of gradations, whereas many philosophers, he says, “have tended to assume there are sharp divides: these are conscious, those are not; these have minds, those do not.” But as Darwinists, he states, “we're going to have to get used to the idea that probably none of those distinctions are sharp.” And it is in simple animals, which have very simple forms of cognition, that this becomes particularly interesting.

“Even in organisms like plants and fungi, as well as bacteria, there is a form of sensing. And there's responding to what they sense. There's memory in many cases: even bacteria have a tiny glimmer of what one might call short-term memory. And somehow, we're going to have to develop a picture of the mind in which we can make sense of these cases where mind appears to be neither wholly present nor wholly absent.” It’s a kind of grey area problem, Godfrey-Smith concludes, such that “philosophy of mind is more or less forced to grapple with as a consequence of the Darwinian picture” (Godfrey-Smith, 2022).