Peter Godfrey-Smith. Metazoa.

Peter Godfrey-Smith

Metazoa: Animal Life and the Birth of the Mind (2020)

In a paragraph

Minds and felt experience emerged through the evolution of animal bodies, nervous systems, sensing and action. Consciousness is not something added to physical processes but the inward aspect of certain organised biological activities, developing gradually rather than appearing at a single threshold. Different animal lineages embody different forms of subjectivity, while richer capacities such as memory, imagination and reflective selfhood are later elaborations of more basic sentience.

Key points

• Minds are evolutionary products arising from non-mental biological processes.

• Consciousness is felt experience: there being something it is like to be an organism, not necessarily reasoning or self-reflection.

• The mind is not caused by brain activity as a separate product; mental activity is organised biological activity viewed from within.

• Nervous systems evolved primarily to coordinate sensing and action in increasingly complex animal bodies.

• Subjectivity and agency developed together as animals became centres where sensory information converges and sources from which action originates.

• Consciousness probably emerged gradually, with borderline cases, rather than switching on at one sharply defined point in evolution.

• Sentience is highly likely in vertebrates and cephalopods, and plausible in at least some arthropods, but not in bacteria or plants.

• Different animal lineages may possess very different architectures and forms of subjective experience, as illustrated by fish, arthropods and the decentralised nervous system of the octopus.

• Basic sentience should be distinguished from later capacities such as episodic memory, dreaming, planning, imagination and reflective selfhood.

• The evolutionary and biological story makes the mind-body problem less arbitrary, but does not fully explain why some organised neural activity is felt while much other coordinating activity is unconscious.

Comments

Peter Godfrey-Smith is an Australian philosopher with an interest is scuba diving.  In Metazoa he uses diving experiences to frame a discussion of the variety of animals that have evolved and philosophical reflections about the likely variety of conscious life that this implies.  The book reflects combined expertise in biology and philosophy and is engaging and considered. I recommend the audible version read by the author.

The point is well made that the evolutionary story shows that central nervous systems evolved to provide sensing, action and control for a wide range of animal bodies.  But we know from our own case that only a small part of the brain’s coordinating activity enters conscious experience.  Therefore, for other animals, we would expect their conscious experiences to relate to their way of life, but still could be very strange.

Links

Book on Amazon UK

Peter Godfrey-Smith website

EXTRACTS

1.  Protozoa

Living activity is not explained in terms of a mysterious ingredient, but in terms of intricate structure on a tiny scale.

The hard part of the mind-body problem is explaining that last side of our mental lives, explaining in biological, physical, or computer-based terms how felt experience can exist in the world.

This project is to show that somehow a universe of processes that are not themselves mental, or conscious, can organize themselves in a way that gives rise to felt experience.

Minds are evolutionary products, brought into being by the organization of other, non-mental ingredients in nature.

A materialist view does not claim that the mind is an effect of physical processes in our brains, a consequence or product of them. The idea, instead, is that experiences and other mental goings-on are biological, and hence physical, processes of a certain kind.

Brain processes are not causes of thoughts and experiences; they are thoughts and experiences.

Metazoa approaches the puzzles of mind and body by exploring the nature of life, the history of animals, and the different ways of being an animal that surround us now. By exploring animal life, we build around the problem and see it transform and subside.

2.  The Glass Sponge

Within any cell is a ‘molecular storm.

But life did not have to do this; it evolved in water—perhaps in thin films of water on a surface, but in water—through the emergence of order in a molecular storm.

If bacteria invented transistors, what were they doing with them? Why did they need to control electricity with electricity?

Within living systems, the activities that look like the things computers also do—electrical switching and ‘information processing’—are always embedded within a sea, a mini-ecology, of other chemical processes.

3. The Ascent of Soft Coral

Animals arose from a particular kind of single-celled organism, larger and more internally complex than bacteria. These cells, eukaryotes, have special devices for handling energy—mitochondria—and an elaborate internal skeleton (the cytoskeleton).

As everyday concepts, subjectivity and agency gesture toward different aspects of a person or animal, a more sensory side and a more active side. From an evolutionary point of view, however, these are closely tied together. Sensing has its raison d’être in the control of action.

I am influenced by the thinking of the Dutch psychologist and philosopher Fred Keijzer, and his emphasis on the shaping of action as a central concern in the early evolution of nervous systems.

4.  The One-Armed Shrimp

The Cambrian, beginning about 540 million years ago, seems to see a sudden shift, almost a rupture. Among its fossils are animals with hard parts, legs and shells, and conspicuous eyes.

That is the arthropod way of evolving: when in doubt, add some legs.

5. The Origin of Subjects

We are subjects-and-agents together.

When an animal picks up information of various kinds through the senses, it becomes a point at which lines converge. When it is an initiator of action, it becomes a point from which causal lines diverge.

An animal is also a place where the present intersects with the past; your handling of the present will be affected by what you have seen before.

The fact that we can imagine a soul with no body, or a body with no soul, doesn’t show anything about what can really be separated.

In the particular area of understanding experience, for some reason it seems hard to simply acknowledge traffic between living systems and the world, with sensing and acting coexisting in a two-way process. Philosophical attention seems to veer wildly from one side to the other.

A balance between my presence and the presence of surrounding things.

6.  The Octopus

7.  Kingfish

Such a lot of the fish way of being was on display: speed and power, bodily sensitivity through long-distance touch, and the schooling that this enables.

8.  On Land

9.  Fins, Legs, Wings

10.  Put Together by Degrees

The theory proposed, in different forms, that a single capacity for ‘mental time travel’ is involved in both looking forward and looking back. The combination of unreliability and vividness seen in episodic memory is part of what suggests that it is a byproduct of a skill in exploring possible futures.

This package of offline abilities, the ability to take ourselves away from what is actually around us, is an important part of the human mind. Dreaming [is] continuous with other offline activity, including daydreaming, exploration while dozing, and episodic memory itself.

The guiding idea has been that the story of mind and felt experience comes out of the story of animal life.

If materialism is true, then the storms within cells, the threading together of countless cells’ activity, the perturbed rhythms of their electrical breathing, and their large-scale coordination are the stuff of mind. This is what we are asked to identify with—not to think that our minds are a consequence of this, but that our minds are such activities.

The imaginative leap is to the idea that we are not extra, not additions to the physical world, but aspects of its workings. We are of these activities rather than merely tied to them or made by them.

Experience is the activity described above as felt from the inside. It is the way things feel for a system that has the right kind of activity in it.

The only organisms that feel their lives have nervous systems, therefore only animals… Sentience is not absolutely everywhere, even within life. But there is a lot of it.