There is, in the long argument the natural sciences have with themselves about what minds are for, a small and difficult animal that refuses to be a footnote. The common octopus — Octopus vulgaris, a name as ill-fitting as any in the binomial registry — possesses some five hundred million neuronsMore than a dog. Fewer than a human. The number, however, was never the point.. Two-thirds of them lie outside its brain.
They are distributed, instead, into the eight arms. Each arm, having its own swelling of nerve tissue, can taste, decide, recoil, reach. It can solve a puzzle of which the brain in the center of the body has not yet been informed. It can, in the technical sense, change its mind without consulting itself.
On the architecture of disagreement
What troubles the biologists, when they let themselves be troubled, is not the strangeness of this so much as its plausibility. Mind, we have long argued, is a unitary thing — a thinking it, in Descartes' phrase, located behind the eyes. The octopus is a polite refutation. It moves as one. It hunts as eight. It is, by every measure we know how to apply, awake; and there is no single place inside it where the lights are onA phrase borrowed from the neurologist Antonio Damasio, who used it to describe consciousness as a kind of household economy..
Consider, if you will, the possibility that the mind has always been a confederation. The octopus is only honest about it.
I spent three days last August in the marine laboratory at Naples, in a room whose temperature was held at a careful sixteen degrees. The tank held a young female who had been there long enough to have opinions about the staff. She liked the postdoc from Lisbon and disliked, in a sustained and theatrical way, the German technician who fed her. She would change color when he entered the room. She would extend an arm, very slowly, as if to point.
The problem of the second self
It is not difficult to project intelligence onto an animal that watches you. What is difficult is to imagine the geometry of that intelligence from the inside — to imagine a self that is also, in some practical sense, a small parliament. The neuroscientist Peter Godfrey-Smith has written that the octopus is the closest thing we have to meeting an intelligent alien. I think this is true and I think it understates the matter. The alien lives inside our own ocean.
There is a parable here for our own species, which has always been more comfortable with the fiction of a unified self than with the fact of one. Every act of attention is a delegation; every emotion, a region of the body putting in a vote. The octopus is not, in this respect, more divided than we are. It is merely less embarrassed.
What does it mean to know something, in eight places at once, that none of those places can put into a sentence? The question has not been answered. It may not be answerable in our register. But the octopus, indifferent to the question, continues. She unfolds. She reaches. She decides — wherever, in her quiet republic, decision happens to live that afternoon — and the arm goes where it goes, and the rest of her finds out in time.