Intelligence Observed

Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness

by Peter Godfrey-Smith

“Mischief and craft are plainly seen to be characteristics of this creature. —Claudius Aelianus, third century A.D., writing about the octopus” 




What is the nature of intelligence and what are its signs? We often use humankind as the standard for questions like these but this book explores a distant branch of the tree of life for signs of intelligence; specifically the cephalopods, consisting of the squid, the cuttlefish, and above all the octopus. The author, Peter Godfrey-Smith, a distinguished philosopher of science and a skilled scuba diver, uses his encounters with these creatures as a jumping off point for exploring questions of evolution, consciousness, and intelligence among animals that are almost as alien as extra-terrestrial beings.

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.