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…”
I have found the magnificent octopus endlessly fascinating. Unfortunately, our history with them—as is mostly the case with other creatures—is not glorious. But, on the positive, we have just begun to really study and respect them.
A story comes to mind of an oceanic explorer who has spent some time with them. He is astounded by their curiosity and friendliness. He does warn, however, to not give them a retractable measuring tape if you want it back. You won’t get it returned. They love them and seem to have found an endless study and application for them. I personally believe they’re just playing with them. Who wouldn’t?
About consciousness—that’s another topic, just hinted at here. Later for that.