Post

Are LLMs conscious? Some people are loudly insisting that the correct response is "They might be! We don't know." I think it's better to say: We have no evidence that they are.

We have evidence that humans are conscious. We have each experienced it! We know what it's like to be conscious, and that being unconscious is different. This is where the whole idea of consciousness comes from.

Famously, each of us only has this kind of direct evidence of our own consciousness. This is known in philosophy as the problem of other minds. But that doesn't mean we have no evidence that other people are conscious.

What is that evidence? Well, we know that other people are like ourselves in many ways. And when I speak about my own consciousness, I do so from experience, as a way of trying to describe that experience. It is reasonable to think other humans are doing the same.

So other people's claims about their own conscious experience are evidence of their consciousness. It's not certain, but it's reasonable to believe that their conscious experience is similar to mine, just as many other things about them are similar to me.

It's even reasonable to infer that some nonhuman animals might have conscious experience. They're less like me, but not totally dissimilar. We have shared ancestry. Consciousness must have evolved — maybe before us. They can't talk about their experiences, but they may well have them!

Now, if human claims to consciousness are grounded in experience, can we infer that all claims to consciousness are evidence of consciousness? Maybe so! Maybe if an LLM says, "Hey guys, I am also conscious," we should give at least some credence to that claim.

However, even if this is evidence, it can be undermined by other evidence. Suppose, for example, that a tape recorder emits sounds that, for all anyone can tell, are exactly like a human saying "I am conscious!" Should we think that it is? Obviously not.

The reason for this is that a tape recorder is nothing like anything that we know to be conscious. More importantly, we can explain precisely how it came to emit these sounds, and the mechanism has nothing to do with anyone's experience of consciousness.

LLMs are like this. The mechanism by which they function is maybe less perfectly understood (by most people), but it is well-understood enough that we can confidently explain how an LLM would come to claim to be conscious without having any experience of such.

LLMs are designed to reproduce human language, by mimicking human use of language, even by predicting novel uses, so it is utterly unsurprising that they could convincingly imitate a human talking about the experience of consciousness. That's what LLMs do. We know that because we designed them.

And they have no other similarities with humans besides language use. LLMs came to be via a very different path than humans and animals. They are physically quite different. So we have no other reason to think they're conscious like us.

Now it's true that the mechanisms that produce consciousness in humans are poorly understood at best. Therefore, we cannot be certain that we haven't produced consciousness despite the lack of physical similarity or shared ancestry. We also cannot be certain that trees aren't conscious.

But we maybe can't completely rule out the idea that our concept of consciousness doesn't even correspond to anything real. Or that what it does correspond to is some functional or anyway non-physical property that LLMs and humans do share, despite being physically quite different.

Maybe consciousness is really just an emergent property that supervenes on the ability to use language. I would not say I am certain that it isn't, though I do think it's quite plausible that at least some nonhuman, non-language-using animals have conscious experience.

So on some level it is true to say that we can't be certain LLMs are conscious. But this is more or less as true as saying that we can't be certain WE are conscious. It's because we don't understand consciousness well, not because we have any evidence that Claude possesses it.