Sy Montgomery has spent her career asking what it is like to be another animal — to inhabit a form of awareness that is related to ours by deep evolutionary time but shaped by a radically different body, environment, and set of problems. The Soul of an Octopus is her account of four years spent with the octopuses at the New England Aquarium in Boston, and it is one of the most quietly extraordinary books about consciousness written for a general audience.
Getting to Know an Alien Mind
The octopuses Montgomery meets over the course of the book — Athena, Octavia, Kali, Karma — are described as individuals with distinct personalities. Athena is exploratory and bold; Octavia is cautious and observational; Kali is playful to the point of mischievousness. The aquarium staff confirm these characterisations independently, and the scientific literature on octopus personality variation backs them up.
What makes this credible rather than sentimental is Montgomery’s background as a rigorous naturalist. She does not project human emotions onto the octopuses; she observes specific behaviours and notes what the animals actually do. The question she keeps returning to — what kind of mind produces this behaviour? — is one that neuroscience is still far from fully answering.
The Question of Consciousness
An octopus has a distributed nervous system: about two-thirds of its neurons are in its arms, not its brain. Each arm can act semi-independently, responding to stimuli and solving problems without instructions from the central brain. The octopus is, in a genuine sense, eight semi-autonomous beings coordinated by a central hub — a form of consciousness so foreign to our own that it forces a rethinking of what we mean by a “mind.”
Montgomery brings in neuroscientists, marine biologists, and philosophers to contextualise her observations. The book never overclaims — it doesn’t argue that octopuses are conscious in the way humans are. It argues, more carefully and more usefully, that they are conscious in some way, and that our failure to take that seriously has consequences for how we treat them.
An octopus is not a simple animal. It has a mind — different from ours in almost every particular, but a mind nonetheless, engaged with the world, with other beings, with problems worth solving.
— Sy Montgomery, The Soul of an Octopus
6 Key Ideas From This Book
Octopuses diverged from the vertebrate lineage roughly 750 million years ago — long before the vertebrate brain evolved its current complexity. Their intelligence evolved entirely independently, which means that complex cognition is not a feature unique to our evolutionary branch but a solution that evolution discovered at least twice.
Individual octopuses show consistent behavioural differences — in boldness, curiosity, aggression, and playfulness — that persist across contexts and over time. This is the definition of personality. Montgomery's careful observations, supported by laboratory research, make a compelling case that individuality is not a human or even vertebrate trait.
Octopus skin contains photoreceptors — cells sensitive to light — distributed across its surface. The octopus may be able to sense colour through its skin despite being colour-blind in its eyes. This is consciousness distributed through the body in a way that has no parallel in human neurobiology.
Octopuses explore their world primarily through their arms — tasting and touching simultaneously, since their suckers contain chemoreceptors as well as mechanoreceptors. For an octopus, to touch something is to know it in a way that has no human equivalent. Montgomery's descriptions of being touched by an octopus are among the most affecting passages in the book.
Octopuses live for only one to three years. In that time they learn, problem-solve, and develop individual personalities. This raises a genuine puzzle: evolutionary pressure to develop intelligence usually comes from the need to accumulate and use knowledge over long periods. What evolutionary pressure produced octopus intelligence in an animal with such a short life?
The book's implicit ethical argument — never laboured — is that evidence of intelligence and individuality creates moral obligations. The aquarium staff's evident care for the octopuses as individuals, and their grief when the animals die, models a relationship to non-human intelligence that does not require certainty about consciousness to be ethically appropriate.
Any Weaknesses?
The book is organised around Montgomery’s personal experience at the aquarium rather than around a scientific argument, which means the science is interspersed somewhat irregularly. Readers wanting a more systematic account of cephalopod cognition should also read Peter Godfrey-Smith’s Other Minds, which covers the neuroscience in greater depth.
Some chapters deal with the personal lives of the aquarium volunteers and staff in ways that, while humanising, occasionally distract from the central subject.
Anyone curious about consciousness, intelligence, and what it means to be a mind in a radically different kind of body — approached through one of the most accessible and personal accounts available.
Other Minds by Peter Godfrey-Smith for the deeper neuroscience, and The Sounds of Life by Karen Bakker for the broader question of non-human intelligence and how we access it.
Philosophers of mind. Montgomery's careful observational approach to questions about consciousness provides a natural history grounding that much philosophy of mind lacks — the actual behaviour of an actual non-human mind, observed up close.
You will grieve when the octopuses die. Montgomery describes their deaths with honesty and without false comfort, and the brevity of octopus lives — often less than two years — gives the book a poignancy that accumulates rather than announced itself.
Frequently Asked Questions
Is The Soul of an Octopus worth reading?
The Soul of an Octopus is one of those books that permanently expands your sense of what minds are and where they live. Montgomery's combination of scientific rigour, personal warmth, and genuine philosophical curiosity makes this essential reading for anyone interested in the nature of consciousness or the moral status of non-human animals.
Who should read The Soul of an Octopus?
Anyone curious about consciousness, intelligence, and what it means to be a mind in a radically different kind of body — approached through one of the most accessible and personal accounts available.
What is The Soul of an Octopus about in one sentence?
Sy Montgomery has spent her career asking what it is like to be another animal — to inhabit a form of awareness that is related to ours by deep evolutionary time but shaped by a radically different body, environment, and set of problems.
The Verdict
The Soul of an Octopus is one of those books that permanently expands your sense of what minds are and where they live. Montgomery's combination of scientific rigour, personal warmth, and genuine philosophical curiosity makes this essential reading for anyone interested in the nature of consciousness or the moral status of non-human animals.
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