There’s no clear way of evaluating consciousness in other animals (or in other humans, for that matter—it’s quite possible that you’re the only conscious being alive and everyone you know is merely displaying signs of consciousness rather than truly experiencing it). But we can certainly make educated guesses. Broadly speaking, consciousness is often defined as there being an experience of what it’s like to be said creature. (This notion is explored in depth in philosopher Thomas Nagel’s essay, “What is it like to be a bat?”)

Octopuses display signs of curiosity, and Godfrey-Smith believes it’s extremely likely that they’re conscious beings. “I think the exploratory behaviors, the fact that they attend to things, they have good eyes, they evaluate, are little bits of good evidence that there’s something it’s like to be an octopus.

Part of this is impressionistic; Godfrey-Smith acknowledges that they simply look like intelligent, conscious creatures. But they also perform certain tasks that are known to be conscious in humans. “Dealing with novelty, when you attend to a novel thing, is always conscious in humans,” he adds.

Given the distant common ancestry between octopuses and humans, conscious octopuses would mean that consciousness has evolved on earth twice. Godfrey-Smith believes it’s plausible that there are more than two branches of evolution where consciousness independently developed.

It’s important to figure out whether consciousness is “an easily produced product of the universe” or “an insanely strange fluke, a completely weird anomalous event,” says Godfrey-Smith. Based on the current evidence, it seems that consciousness is not particularly unusual at all, but a fairly routine development in nature. “I suspect animal evolution, if were replayed again, it would produce subjectivity of a somewhat similar kind,” he adds. “You can see why it makes biological sense.”

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