What if intelligent life on Earth evolved not once, but 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 nature became aware of itself – a story that largely occurs in the ocean, where animals first appeared.
Tracking the mind’s fitful development from unruly clumps of seaborne cells to the first evolved nervous systems in ancient relatives of jellyfish, he explores the incredible evolutionary journey of the cephalopods, which began as inconspicuous molluscs who would later abandon their shells to rise above the ocean floor, searching for prey and acquiring the greater intelligence needed to do so – a journey completely independent from the route that mammals and birds would later take.
But what kind of intelligence do cephalopods possess? 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’? 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.
Deftly blending philosophy and evolutionary biology, Godfrey-Smith (Darwinian Populations and Natural Selection), an Australian philosopher of science, uses his passion for cephalopods to address "how consciousness arose from the raw materials found in living beings." Comparing vertebrate consciousness and intelligence with that of cephalopods is not as odd as it might seem, because "cephalopods are evolution's only experiment in big brains outside of the vertebrates." Godfrey-Smith demonstrates that octopuses are constructed from a dramatically different plan than vertebrates, with each of their arms having the ability to act and sense their environment semi-autonomously from their central brains. This striking difference raises intriguing questions about the nature of communication within organisms, as well as about the meaning of intelligence. Godfrey-Smith couples his philosophical and scientific approach with ample and fascinating anecdotes as well as striking photography from his numerous scuba dives off the Australian coast. He makes the case that cephalopods demonstrate a type of intelligence that is largely "alien" to our understanding of the concept but is no less worthy of wonder. He also ponders how and why such intelligence developed in such short-lived creatures (they generally live only a few years). Godfrey-Smith doesn't provide definitive answers to his questions, but the journey he leads is both thoroughly enjoyable and informative.