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Lori Marino's avatar

Hi Walter,

Thank you for your thoughts on this matter. You are right on point about the fact that consciousness is the outcome of a Darwinian process. And without understanding how nervous systems and brains evolve one is handicapped to understand the nature of mind.

You state that “Evidence from Homo sapiens sits alongside evidence from other species.” I agree entirely. However, I think that sometimes theorists get trapped into thinking that the approach to studying any phenomenon is “top down” or “bottom up”. But that stance buys into a scala naturae viewpoint that accepts the false idea that evolution is about a linear progression towards humans. So, I say that we try to open this conversation up by avoiding linear concepts like these.

Another way that we tend to get trapped by false notions is by deconstructing species and evolutionary processes into discrete units instead of the continuous variable that it actually is. This is when we make the fundamental mistake of thinking that every species has arisen de novo and has a qualitatively different experience of life than every other. So now we are faced with “human consciousness” and “giraffe consciousness” and “fish consciousness” ad absurdum. This is a non-starter position.

It goes without saying that every species is a variation on a theme. And members of that species are going to perceive and act in the world as a product of their particular adaptive history. But this does not mean there is discontinuity across species in mind. Studies of brain evolution and anatomy tell us that there is, in fact, tremendous continuity and conservatism in the evolution of psychology. For example, there are highly conserved systems in the brains of all vertebrates that – given all the evidence - do pretty much the same thing whether one is a sperm whale or an aardvark. How could it be otherwise? It would be preposterous to think that the same structures do something completely different in each and every species. This does not mean that being a sperm whale is like being an aardvark. But it does require nuanced thinking about how evolution actually works. And it requires that we hold in mind the fact that humans and other species are alike and different - all at the same time.

Thanks so much for this important discussion. All best, Lori

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Walter Veit's avatar

Thanks for the comments! I agree completely. I think one of the problems with de Weerd’s understanding of my bottom-up approach is exactly the narrow characterization you describe. But I think of a “bottom-up” approach in terms of the tree of life, with a great diversity of branchings, rather than a single scale. So I am not fully convinced that the bottom-up framing must imply a a scala naturae - which I certainly reject.

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Lori Marino's avatar

I certainly agree with the way you use the "bottom up" approach.

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Pete Mandik's avatar

unclear whether you think “meta-cognition, self-awareness” are uniquely human or whether instead it’s “complex…meta-cognition, self-awareness” that you’re claiming are uniquely human. The former is difficult to believe. The latter is difficult to assess.

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Walter Veit's avatar

Unique human forms of them. Of course it may turn out that even those are shared by other animals, e.g. elephants. But I don't think these capacities gave rise to consciousness.

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Pete Mandik's avatar

of course the forms unique to humans are unique to humans. but now you have no complaint against someone who thinks consciousness, even in nonhumans who have it, requires metacognition or self-awareness

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Walter Veit's avatar

Agreed, minimalist forms could also function as potential explanations for consciousness. In my book, I argue against either pathway.

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Matt Ball's avatar

Thanks Walter. This is very interesting. I think I mostly agree with what you say in this, although I think we have a more fundamental difference of opinion. 🤷‍♂️ I will keep reading your future ones. Happy New Year to you and yours!

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Walter Veit's avatar

Happy New Year to you too! Curious to hear where you disagree!

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Matt Ball's avatar

I think I'll know more from your upcoming pieces, but here is one bit https://www.mattball.org/2025/12/what-is-consciousness-with-many-links.html

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Walter Veit's avatar

Looks like our disagreement is about invertebrate consciousness. When it comes to insects, I've argued that they are plausibly capable of having positive and negative hedonic experiences for motivational trade-offs, even in the absence of pain. For decapod crustaceans I find the evidence for pain-like states very compelling and I'll probably make a post about that while writing my book.

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