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

by Peter Godfrey-Smith

The central idea is that rather than mediating between sensory input and behavioral output, the first nervous systems came to exist as solutions to a problem of pure coordination within the organism—the problem of how to coordinate the micro-acts of parts of the body into the macro-acts of the whole. The cephalopod body, and especially the octopus body, is a unique object with respect to these demands. When part of the molluscan “foot” differentiated into a mass of tentacles, with no joints or shell, the result was a very unwieldy organ to control. The result was also an enormously useful thing, if it could be controlled. The octopus’s loss of almost all hard parts compounded both the challenge and the opportunities. A vast range of movements became possible, but they had to be organized, had to be made coherent. Octopuses have not dealt with this challenge by imposing centralized governance on the body; rather, they have fashioned a mixture of local and central control. One might say the octopus has turned each arm into an intermediate-scale actor. But it also imposes order, top-down, on the huge and complex system that is the octopus body.