Octopuses—those rascally, shape-shifting, skin-changing, critters of the sea—are, like all forms of life, unique. Watch them—as they scamper across the sea-floor, open a jar from within, change the color of their flesh in a heartbeat (of which they have three) through a startling range of colors and patterns, wield coconut shells or seashells as tools, or ensnare an unlucky target in an elegant tangle of tentacles—and you behold a creature seemingly extraterrestrial in its form, yet somehow familiar in its mental faculties.

Consider Inky: Previously a captive denizen of the National Aquarium of New Zealand, Inky made headlines this year after he managed to slide the lid off of his tank, climb up and out of it, slither across the floor, squeeze through a drainpipe, and return to the ocean, an episode described by National Geographic. “He was very inquisitive,” the manager of the aquarium told that publication, “and liked to push boundaries.”



Aristotle had a different take on Inky and his ilk. “The Octopus,” he wrote in the History of Animals, “is a stupid creature, for it will approach a man’s hand if it be lowered in the water…” What others might see as a sign of inquisitiveness, Aristotle took for idiocy. To his credit, Aristotle did accurately describe some of the other aspects of the octopus, including its ability to change “its color as to render it like the color of the stones adjacent to it” while hunting, or when startled. He also described its precarious and short life, and the death that comes soon “after the birth of the little octopuses.”

Wily, short-lived escape artists and masters of disguise, perhaps. But can we say more? Can the beasts think? Can they feel? Do they have, that is to say, the gift—and sometimes the curse—of consciousness?

“Plato,” Bertrand Russell began his essay Mind and Matter, “reinforced by religion, has led mankind to accept the division of the known world into two categories—mind and matter.” This dualism was famously reformulated by René Descartes, who also pinpointed the essence of the mind to a rather curious part of the brain, the pineal gland. Although many have since sought to call the mind-matter question a closed case (including Russell, who concluded that the “whole problem vanishes” if only people accepted his argument), the question of “mind”—or more precisely, the problem of consciousness—remains as thorny as ever. Why do we consciously perceive the world, and with what living things do we share this faculty?