Other Minds

Cephalopods & Evolution

Octopus, Squid, and Cuttlefish of the cephalopod class of animals have well-developed intelligence, but branched evolutionarily from vertebrates before the development of intelligence. They are like alien intelligence on earth. All other intelligent animals developed from an already-intelligent ancestor.

When there were only single-celled organisms they sometimes lived in communities, (as they still do today). Groups of cells communicate chemically, and eventually some communities became one organism, perhaps through a failed cell division, and they continue to communicate. Near the end of the Ediacaran period an evolutionary split occurred, one branch went on to become molluscs, then cephalopods and the other to become vertebrates. The last common ancestor was a bilateral animal and would have had some basic nerves and maybe sense organs, but no organized intelligence or large nervous system.

As the Ediacaran period came to a close and the Cambrian period started, animals began to scavenge and predation started, creating the evolutionary pressure that fueled cambrian explosion.

Distributed Brains

Cephalopod brains are extremely different from vertebrate brains. There is more "brain" outside of the brain than in the brain. Parts of the body, for example legs, appear to be self-governing and independent, but work together as a single animal.


Octopus are curious, mischievous creatures with personality, and Cuttlefish transform their colours in ways that appear very individualistic. When captured octopus will mess with their environment, and squirt people who come near their enclosure. Sometimes they squirt with certain people, not just people in general. Behavioural experiments with octopus are very difficult because they do things to the experiment itself, unlike rats or other animals often used in behavioural studies.

Octopus are not thought to be social, but they have been observed to give each other "high-fives" at the Octopolis site near Australia. This and some other research, (mentioned in the Octopolis chapter near the end of the book), suggest maybe they are more social than originally thought.

Consciousness, Experience, and Higher-Order Thought

What is consciousness, exactly? What is it like to be something?

There are competing latecomer and transformation theories of consciousness. The latecomer view says that consciousness developed recently, after things like working memory, whereas the transformation theory says that consciousness pre-dates things like working memory and workspaces. If consciousness is not boolean, but is a scale, it seems like transformation makes more sense. The latecomer view that consciousness is a fairly high-level process logically opens the door to a level of lived experience that doesn’t qualify as consciousness. Multiple ways to experience the same thing, which feels linked to the idea of perceptual constancy, or the ability to recognize something despite viewing it from different angles, or experiencing it in different ways.

Language is not needed for Higher-Order Thought

There was a debate about if language was required for higher-order thought. In the 18th century philosopher David Hume "looked inside his mind" and saw thoughts, but didn’t mention words. 200 years later John Dewey suggested that the "thoughts" that Hume saw were words, and in the 20th century Lev Vygotsky went so far as to suggest that as children learn speech they get conscious thought!

However, baboons, (Chapter 5), only make four sounds, but by hearing those four sounds made by many different individuals they understand the complex social structure of their group, and changes to that structure as it occurs. There is also evidence deaf people in pre-literate societies, (so they wouldn’t have had a way of having language), lived full lives, (Chapter 6). There’s even Brother John, a Qu├ębecois monk who lost the concept of language for periods of time, bit during those times he had thought and desires, and was able to communicate them to others.

With the evidence of baboons, Brother John, and some studies on birds it becomes clear that language, while very useful for organizing our thoughts, is not required for higher-order thought. Language, inner speech, and thinking about thinking are a way to engage in slow, deliberate Daniel Kahneman System 2 thinking. This is where I was surprised to link Other Minds, a philosophy book about octopuses and consciousness, with Cortex, a podcast about doing stuff!

At the end of Chapter 5, on colours, Peter Godfrey-Smith says that because cephalopods "language" appears to be colour and skin patterns, and they can’t see themselves, then they must not be capable of inner dialogue. Inner dialogue would be easier with language, but I suspect that it is possible without language, like higher-order thought.

Consciousness as a Workspace

The workspace theory of consciousness suggests that our consciousness is the workspace where we put thoughts that we are working on. Most tasks are handled unconsciously by our nervous system, but when we encounter something particularly novel we have to think about it, so it enters our consciousness. The workspace theory may also be thought of as broadcasting, like an event system in programming, when a new or difficult tasks arrives we say "this is what we’re working on" so we can think about what we think about, and understand that what we can influence ourselves by, for example, entering a to-do item in Omnifocus.

Only having novel experiences rise to the level of actually needing consciousness fits nicely into the theory that life feels like it’s passing by quickly when we stick to our routines.

Change Experience by Interacting With It

When we interact with the world we change it, and our experience of it, and by keeping an efference copy of our thoughts and interactions we understand that we have changed the world and our experience of it. This is another example of our mind thinking about thought. Some philosophers believe, (Chapter 4), that we don’t change our experience of the world, that we are simply "rocks in a stream of consciousness," but this seems silly – surely we can influence the world, and if we can think about thinking, we must be able to change how we perceive it as well.


Cephalopods, especially cuttlefish, can do amazing things with their colour and texture on their bodies. The book describes in detail how colours are created, but the how, while fascinating, doesn’t seem as important as the why. Individuals have individual patterns, but there are some themes. Individual cuttlefish even seem to have their own idle animations, which may be an external expression of any random thoughts they have, (or maybe digestive discomfort, we don’t really know).

We don’t truly know why cephalopods have such an amazing ability to change colour. They use it for camouflage, but it seems like it is also used to communicate, especially to confuse or threaten other species.

Something particularly weird is that it doesn’t look like cephalopod eyes can see colour, so why do they make so much colour? On the other hand, cephalopods have light receptors in their skin all over their bodies, which could be used with the colour-forming systems in the body to understand colour in their environment.

Short Lives & Aging

Cephalopods live remarkably short lives. Octopus only ever have one brood of babies, cuttlefish die after their first breeding season. This is strange among large-brained animals, and led to a fascinating discussion of aging and were it might come from.

Why do we age?

Individual cells come & go, but a community of cells can, (and do), live indefinitely. Since animals are just large communities of cells, why do they age, when communities of single-celled organisms don’t?

It turns out that there’s a theory that makes a lot of sense for organisms that reproduce at a mostly constant rate throughout their lives, (like people, and many animals). The theory is that organisms started able to live forever, but that every year some number of the community are eaten or die in accidents. If this chance of death is relatively constant eventually math catches up with most individuals and they are killed. If there’s a relatively constant reproduction rate, more young are produced by younger members of the community, because younger members haven’t been killed yet, and any evolutionary mutations that negatively affect old individuals aren’t weeded out because individuals die from other reasons before those mutations cause problems, and by that time they’ve had lots of babies to pass the mutations on to. So aging is a collection of evolutionary mutations that affect old individuals.

But Trees?

Trees, and organisms that increase their reproductive power with age, may have the opposite evolutionary force at play.

Short lives in Cephalopods

If individuals need to live for quite a while to spread their young at a constant reproductive rate, then evolution would reward species with a large chance of accidental death if they reproduce as fast as possible. Since cephalopods have no shells, are soft, delicious, and have to wander around and hunt, they have a high chance of being killed early in life, so it seems that they have evolved to have an all-in approach to reproduction where they go so hard the first time that it kills them.


I’m pretty sure this is the first philosophy book that I read, and it is fascinating. The link between consciousness, higher-order thought, organized thought, and recognition is particularly interesting and I haven’t been able to explain, or fully comprehend, it like I would like to. The discussion of aging near the end of the book is a hidden gem that makes the silicon-valley billionaires who are trying to solve aging seem slightly less eccentric.

It took me a while to get through Other Minds, but I’m glad I did. There is a lot to think about, and I understand consciousness better, or at least understand some questions to ask.

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