Although mammals and birds are widely regarded as the smartest creatures on earth, it has lately become clear that a very distant branch of the tree of life has also sprouted higher intelligence: the cephalopods, consisting of the squid, the cuttlefish, and above all the octopus. In captivity, octopuses have been known to identify individual human keepers, raid neighboring tanks for food, turn off lightbulbs by spouting jets of water, plug drains, and make daring escapes. How is it that a creature with such gifts evolved through an evolutionary lineage so radically distant from our own? What does it mean that evolution built minds not once but at least twice? The octopus is the closest we will come to meeting an intelligent alien. What can we learn from the encounter? In Other Minds, Peter Godfrey-Smith, a distinguished philosopher of science and a skilled scuba diver, tells a bold new story of how subjective experience crept into being--how nature became aware of itself. As Godfrey-Smith stresses, it is a story that largely occurs in the ocean, where animals first appeared. Tracking the mind's fitful development, Godfrey-Smith shows how unruly clumps of seaborne cells began living together and became capable of sensing, acting, and signaling. As these primitive organisms became more entangled with others, they grew more complicated. The first nervous systems evolved, probably in ancient relatives of jellyfish; later on, the cephalopods, which began as inconspicuous mollusks, abandoned their shells and rose above the ocean floor, searching for prey and acquiring the greater intelligence needed to do so. Taking an independent route, mammals and birds later began their own evolutionary journeys. But what kind of intelligence do cephalopods possess? Drawing on the latest scientific research and his own scuba-diving adventures, Godfrey-Smith probes the many mysteries that surround the lineage. How did the octopus, a solitary creature with little social life, become so smart? What is it like to have eight tentacles that are so packed with neurons that they virtually "think for themselves"? What happens when some octopuses abandon their hermit-like ways and congregate, as they do in a unique location off the coast of Australia? By tracing the question of inner life back to its roots and comparing human beings with our most remarkable animal relatives, Godfrey-Smith casts crucial new light on the octopus mind--and on our own.
People interested in such things have spent a lot of time trying to put concrete numbers to the odds of these things happening. That last step – the development of intelligence – seems among the most unlikely, but one of the implications of this utterly fascinating book is that perhaps it isn't so unique after all. Enter – by jet propulsion – the octopus.
Invertebrates are not generally known for their brainpower. But octopuses (and, to a degree, all cephalopods) are an exception. In terms of sheer neurons, they are well up there with many of the mammals – they have more neural connections than cats, for example. As Godfrey-Smith puts it, they are ‘an island of mental complexity in the sea of invertebrate animals’.
That does not mean that the way they think is comparable to us, though, or to your pet Persian. Although a few of an octopus's neurons are gathered into a walnut-sized ‘CPU’ of sorts, most of them are dispersed throughout their body: each of their eight arms can, in a very real sense, ‘think’ and act independently.
Godfrey-Smith, though often wearing a marine biologist hat, is a philosopher by training, and he spends a lot of time here addressing the question of what it might feel like to be an octopus, without a centralised ‘self’ in the way that we understand it. I thought I would find these sections irritatingly speculative (which is my reaction to most philosophers, if I'm honest), but in fact they were so grounded in scientific data, and just so interesting, that I was more than happy to go along for the ride.
Ultimately, though, the differences are perhaps less significant than the similarities. The most recent common ancestor of humans and octopuses lived upwards of five hundred million years ago, and was probably some kind of very simple worm-like thing without any neural network to speak of. That means that natural selection has, completely independently, developed complex ‘intelligence’ of some kind twice.
‘Cephalopods and smart vertebrates are independent experiments in the evolution of the mind,’ Godfrey-Smith summarises. The implications are genuinely awe-inspiring. And looking at an octopus is, in all likelihood, as close to meeting an alien intelligence as we'll ever get.
“Assume we found this animal, and are now watching the departure, the branching, as it happened. In a murky ocean (on the sea floor or up in the water column) we’re watching a lot of these worms live, die and reproduce. For an unknown reason, some split off from the others, and through an accumulation of happenstance changes, they start to live differently. In time, their descendants evolve different bodies.”
Happenstance? The author doesn’t believe it is true, but he basically characterized adaptation and evolutionary change as happenstance. It is anything but. Or is he characterizing an environmental event as happenstance? That I can buy - a tree falls into a stream and causes a disruption of flow, animals and plants living in that stream have to adapt to the new conditions and given enough time, evolutionary change will occur. But it’s unclear which part is happenstance and I hate that. Later he stressed the fact that a simpler or older animal isn’t necessarily lower or lesser and redeemed himself.
Then the writing itself almost did me in. Every time I picked up the book I was irritated. Mostly at the fact that his noun/object relationships didn’t agree a lot of the time (example - octopuses will often reach out their arm to explore...what do they share an arm? ugh!). Then he referred to an earlier point with a different name than he gave it. The brain power conclusion on page 50 was weak, too, but there was enough interesting stuff that I kept going despite sentences like this -
“I think the problems with the old Peter Dews experiment, such as they were, came in part by the assumption that an octopus would be interested in pulling a lever repeatedly to get pieces of sardine, collecting piece after piece of this second-rate food. Rats and pigeons will do things like that, but octopuses take a while to deal with each item of food, probably can’t cram themselves, and tend to lose interest.”
Can’t cram themselves? Where did that come from? Why is that there? OMG. But wait, there’s more -
“When you’re around an octopus, it’s impossible not to think they can also direct considerable attention on objects, especially new ones.” p 101
“Nearly every time this has happened, it has happened only once.” p 114
“We think that a first octopus, of a few of them, made a den at the found object, and began bringing scallops in to eat.” p 188
You get the picture? Anyway, despite the numerous clunkers, there are great bits of information and ideas about consciousness and how it might have evolved. By the end of the book I felt comfortable with consciousness as a spectrum and many places to land. If we can let go of consciousness being just a human trait, we can see it in many animals. Partly it’s because the octopus is so very different from any vertebrate you can think of that Godfrey-Smith says that octopuses are the closest we can get to meeting an intelligent alien.
“In an octopus, the nervous system as a whole is a more relevant object than the brain: it’s not clear where the brain itself begins and ends, and the nervous system runs all through the body. The octopus is suffused with nervousness; the body is not a separate thing that is controlled by the brain or nervous system.” p 75
And this observation by Stanislas Dehaene was really insightful - that the demands of novelty jolt us from unconscious routine to conscious reflection. That is exactly what happens when an octopus becomes curious about something and pauses in its routine to examine it. Oh how I love them.
For a while he switches to giant cuttlefish and their remarkable ability to make mesmerizing kaleidoscopic displays of color which are made all the more remarkable because they are, so far as we can tell, colorblind. There’s an idea that because there are photoreceptor cells present in cephalopod skin that the skin itself can see after a fashion. Part of this seeing might be the ability to separate light into wavelengths and filter it in much the same way colored filters work in black and white photography; for example a red filter will block waves that aren’t red. It’s a reasonable hypothesis that cuttlefish and octopuses sense specific wavelengths of light, then make camouflaging color they cannot see by reproducing the wavelength itself, not the end result (the color).
I also liked the concept of a cuttlefish’s constant state of changing colors as a reflection of internal processes rather than of conscious thought or direction. It’s noise, not signal. Godfrey-Smith did a good job distinguishing that.
In the other book I read about octopuses, the fact that they have short lifespans is brought up, but not explained and it mystified me. Most other animals we consider intelligent live much longer; parrots, dogs, dolphins, chimps and that intelligence and the social arrangements it facilitates make sense to us, but such brain power in an animal that only lives a couple of years seems like a waste. Godfrey-Smith puts forward an explanation that hinges on the fact that evolutionary adaptation made the higher functioning thought processes necessary for the octopus to live and forced it into a ‘go for broke’ style of breeding; that is it happens all at once. Then it’s done and the animal died. It’s more complicated than that, of course, but it made a kind of sense.
It’s a short book and enlightening if you can get past the writing it is definitely worth your time if you’re interested in ideas about sentience and consciousness and how evolution produced it on three separate occasions; twice in cephalopods and in humans and animals like us.
Peter Godfrey-Smith is a philosopher, but also a scuba diver, and his encounters with cephalopods off the coast of Australia led him to this fascinating study of minds, both human and alien. Deep discussion of what consciousness is and how it happens is interleaved with vivid descriptions of octopus behavior and relationships. As a pure philosophy book, this would be too dense and heavy to manage, but bringing in the octopuses and their evolutionary history gives it just the right balance. An enlightening read for anyone interested in the question of animal intelligence and the ways humans are similar to - and different from - very different creatures.
The story begins and largely continues in the oceans from which all life originally came. The evolution of seaborne groups of cells is explored as they gradually became more complicated creatures that were capable of sensing, acting, and signalling, The author identifies gradual evolutionary developments that led to nervous systems in creatures like mollusks. Some of these mollusks abandoned their shells and rose from the ocean floor gradually developing the greater intelligence needed to search for prey and survive. This evolution continued for millennia just as our forebears and other mammals developed on land.
The most fascinating aspect of this story is the search for and discovery of the nature of intelligence in cephalopods. Through observation the author identifies how the brain that is so compactly and centrally located in the human head appears to be spread out throughout the body of the octopus.
“In an octopus, the nervous system as a whole is a more relevant object than the brain: it’s not clear where the brain itself begins and ends, and the nervous system runs all through the body. The octopus is suffused with nervousness; the body is not a separate thing that is controlled by the brain or nervous system.” (p 75)
It seems that in an octopus the nervous system as a whole is equivalent to their brain. A relevant philosophical discussion about how to imagine this is conisidered in Thomas Nagel's famous essay, "What is it Like to Be a Bat?" (Philosophical Review, 1974).
Most interesting for this reader was the way that the evolution of cephalopods has mirrored our own evolution in some ways even as the organisms have developed differently in response to their environments. The author's interaction with a nest of octopuses, in itself a discovery, provided information about the difference of these animals, yet also led to identification of a level of intelligence that was both beyond any previously assumed and far different that that typical for mammals and most other creatures. These discoveries, including tentacles that are so full of neurons that they appear to think for themselves, solved some of the mysteries of these creatures and provided encouragement that further answers will be found.
I understand Godfrey-Smith to be a philosopher, which I don't hold against him...that breed can be rather full of themselves and tend to pepper simplicities with obscure jargon to hide the lack of substance...because he is generous with his restraint. Is this rigorous? Not at all and that is what makes this good for the common reader. Godfrey-Smith writes an eminently readable narrative of a decidedly odd consciousness whose evolution split from ours so very long ago. Details of what we know to date on the neurology and intelligence of the most fascinating branch of Cephalopods are woven around his personal experiences diving off of Australia. I was not expecting explanations (as there are few for this still misunderstood creature) but I also didn't mind the speculations that accompanied the facts (as we know them).
An observation...the title really might have been singular as he focuses on octopuses. But then again, he might have been talking about all octopuses as "other minds", as opposed to other species. Regardless, there's a love affair here, and I'm right there with him.
Of course, as one might expect, there is a fair bit of hand waving in any of the evolutionary scenarios invoked here. There is very little fossil record of octopi due to their fluid makeup. And relatively little direct observation given their preferred locale. Only recently have serious quantitative methods been employed in their study along with genetic sequencing. So much of what is described here is anecdotal, impressionistic, and speculative. That’s not a criticism in itself; it just sets the limits on what you might want to take away.
Godfrey-Smith’s writing is enthusiastic yet workmanly. It is as though he’s taken a concentrated scientific paper and puffed air into it to expand it to book length. The result is a bit disjointed. The opening sections of evolutionary speculation may not sit comfortably with the more rigorous philosophical questions of other minds. And the more purely scientific reportage shades over into personal anecdote. Which might be a recipe for a book that has something for everyone. I at least got enough out of it to keep reading through to the end. And so will you, I suspect.
A deeply (!) enjoyable look at cephalopod minds, not brains but minds, in parallel to our own mammalian ones. I was absolutely enthralled by the author's discoveries made at a site he calls "Octopolis," a community of octopuses on the seafloor near Sydney, Australia.
One of the most interesting facets of the book to me was its explanation, in terms of existing evolutionary thought, of how and why cephalopods, animals that live a single mating cycle on average, developed the astoundingly complex signaling behaviors and apparent cognitive abilities they have. It's a wonderful and involving story.
That makes this sound like a four-and-a-half star book, doesn't it? I'm not going to beat about the bush, it would have been had it not wandered waaay too far down the human-mind-brain-consciousness rabbit hole without reaching any sort of conclusion that felt solid. In the space of this book, just over 200 pages of text plus index and notes, there is no chance that this could occur. So say "listen, there's about a bajillion petaflops of data I can't begin to pretend to digest for you, but here in 500 words is what *I* want you to know so you can see where I'm going with the parts about cephalopods."
The glossy-magazine version, in other words, would've served this book better and been less simultaneously overinforming and underrepresenting a hugely complex and contentious area of human-consciousness study. But I recommend reading the book because damn it feels good to learn about something unique from someone so warm, wise, and witty as Peter Godfrey-Smith.
Secondly, 'Other Minds' is the kind of book destined to become a classic of its genre, as it has a tremendous - I would say life-changing - effect on the reader. This reader included; after reading about the startlingly high level of intelligence possessed by octopuses, I cannot ever see myself ordering octopus as food in a restaurant again. It just seems wrong; they are as characterful as dogs and cats, and I think it would simply be terrible to treat these amazing creatures as a foodstuff any longer. I do hope, given my love of bacon and chorizo, that Godfrey-Smith's next book is not on the topic of porcine intelligence...
And thirdly (for the sake of brevity - I could certainly go on in praise of this book), Godfrey-Smith makes a great case for the protection of the ocean environment. Overfishing and pollution have both taken their toll, and now that we understand how much intelligence - nay, sentience - is present in the depths, we owe it to our genetic relatives (by which I mean all species, in every shape and form) to do a better job of not destroying what life there is out there.
But an entirely different branch of life on this planet also shows surprising intelligence--the cephalopods, including octopuses, cuttlefish, and squid. Their line and ours (that is, the vertebrates) separated hundreds of million years ago. Even our eyes and theirs evolved separately. Most of them live less than five years. They don't appear to be very social.
Yet they have large and complex central nervous systems. Organized very differently from ours, but large and complex nevertheless. They show many signs of being intelligent, curious, and inventive. But why should an octopus that lives only two years, apparently isn't social beyond breeding once, and broods her eggs but dies when they hatch and certainly doesn't raise them, evolve such a complex nervous system and apparent intelligence? What are those expensive resources for?
Godfrey-Smith gives us a really interesting exploration of this question, including tales of his own and others' direct experiences with cuttlefish and octopuses in their home environments, not just in labs. (Though they do some pretty darned interesting things in labs, too.) His own experiences with a cuttlefish, at the end of its breeding season and thus nearing the end of its life, are fascinating.
There is also a lot of exploration here of what consciousness is, how it evolved, and what it really does--for us, and perhaps for cephalopods.
All in all, an absorbing book, grounded in science, and exploring some fascinating territory and ideas.
I bought this audiobook.
The topic of consciousness is only briefly covered, but good points are made.
I enjoyed reading it.
It was also interesting to read about how the first living things lived during the Ediacaran period and how things evolved and came to be what they are today. As the book went on I found it a bit repetitious and boring as some things did not tie in with cephalopods. Once I got a taste of octopus that was all I wanted. But still an enjoyable read overall.