There's a difference between knowing, and knowing how you know. I know my computer is not conscious even if I'm not entirely certain how I know. I chalk this up to the fact that, as a conscious animal with millions of years of evolutionary history, it is both beneficial and entirely natural for me to be able to recognize conscious beings when I encounter them.

(It also helps that I know how to program computers and don't view that activity as bringing consciousness in the world. I have children, however, so it turns out that I am — with some help — also able to bring consciousness into the world. The former activity I am both able to do and fully understand, while the latter I am clearly able to do, but don't at all understand.)

I recognize this point of view isn't popular among a lot of technical folks. I get it, I was there once too, but I've come around to a new appreciation for our animal nature. This question — how do you know what is conscious? — is very similar to questions like, "how do you know that that dog is afraid?" The short answer to that question is, "because we are kin". Which is an explanation I find much more rich and satisfying than reductionism.

That breaks down for anything that is not your kin though. "How do you know the computer is not conscious?" does not allow the answer "Because we are not kin". Best you can say is "Because we are not kin, I don't know". The dog example is illustrative of only half of the question.

I take your point, but I disagree: your statement assumes that there are conscious beings who are not my kin (and to be clear, by "kin" I broadly mean animals: living entities that are embodied and show characteristics like intention, mood and emotion). But there isn't any evidence that these exist and there's little if any evidence that they are even possible.

At best, you can put forward a thought experiment that starts with, "Suppose there are beings which are not animals but which are nonetheless conscious." I'm questioning the premise of that thought experiment, however, because so far as we can tell, there is no such thing.

In other words, computers are not conscious because they are not animals.

This may seem like circular reasoning, but not if you take the view that consciousness is a fundamental property of animals as opposed to an emergent property of complex systems.

No, there's no such assumption in my statement. That statement is merely open about what we don't know. Conversely, there is an assumption in your reasoning that non-animals are never conscious, which is, well, an assumption, and not derived from facts.

This creates a blind spot where an area of non-knowledge is assumed to be known about, and rejected out of hand. I have to point out that taking the view that consciousness is a property of animals does not exclude non-animals having it.

Even then, there will be a tussle over the exact line of what qualifies as an animal for the purpose of consciousness, resulting in the need to answer the same generalizations (e.g. intention, mood, emotion) that would allow yet undiscovered but plausible forms of life to qualify as conscious.

Some great points, well made (and apologies for putting that assumption on you, you are correct about that). I think the blind spot you refer to also creates the risk we may encounter consciousness and not recognize it.

I’ve long been of the common-in-tech-circles belief that at some point in the future we will be able to create intelligent, conscious machines. Where my view on this fascinating issue is shifting is that I’m much less convinced that our animal nature is immaterial to this task.

In any case this has been a fascinating and insightful conversation and I appreciate the opportunity to have it with you and the other commenters here.

I don't think free will matters at all for consciousness.

How is a world where your will is decided by quarks randomly zagging instead of zigging any more open to free will than a deterministic world?

This comment is amazing. Thank you.