curi: The trait that differentiates humans from non-human animals, in a veganism-relevant way, is (general, universal) intelligence, which is the ability to learn (aka create knowledge), which is the ability to do evolution of ideas within one's mind.
This is a binary trait, not a matter of degree.
This is not a complete explanation, e.g. it doesn't say how that trait relates to other issues vegans may bring up like consciousness or suffering.
Vegans: What about mentally handicapped people. If they have less intellectual capacity than a cow, is it OK to kill them?
curi: Yes, in principle. They're (by premise) on the wrong side of the intelligence/non-intelligence asymmetry.
However, we should begin our discussion with cases which are easier to understand and potentially agree about, not hard cases or edge cases. If you understand and agree with my way of differentiating most humans from cows, then it'd make sense to discuss edge cases in detail.
Vegans: How do you tell if a normal person or cow is intelligent?
curi: Primarily behavior: people have intelligent conversations, write blog posts demonstrating that they understand TV show plots, act according to learned jobs skills, develop new science, etc. That is best explained by knowledge the person created in his mind rather than by genetic knowledge. Animals behave in simplistic, algorithmic ways which are best explained by the knowledge in their genes.
I think careful analysis of animal behavior, and trying to differentiate it from the capabilities of stuff like video game enemies and self-driving cars, is one of the more productive ways to continue this discussion. People have strong intuitions that animals are somewhat intelligent and are clearly different, in terms of intelligence, than current robots and "AI" software algorithms. Relatedly, people believe intelligence is a matter of degree. Looking at rigorous information of animal behavior, from scientists, and carefully considering the simplest ways it could be achieved, can be informative.
Updates after talking with bryn and Ask Yourself:
**Vegans:** So if you met a zombie person who's not intelligent, it's totally ok to shoot them in the head with a headgun? (Ignore the issue of property crimes or purpose for doing it.)
**curi:** If I meet a person IRL, I have incomplete information. So I might suspect they're unintelligent, but I wouldn't want to shoot them. Due to incomplete information, I'll err on the side of caution. For example, some people thought Helen Keller was unintelligent before she was able to communicate, but they were mistaken.
**Vegans:** What's the asymmetry between the zombie person and a cow? Why be careful with one but not the other?
**curi:** This is a second, different asymmetry. The main asymmetry for welfare and rights is intelligence. An asymmetry for my caution in this atypical hypothetical case is *human genes vs. cow genes*. Human genes create an intelligent mind over 99% of the time, while cow genes do it 0% of the time, so that's a reason to be more careful around human genes.
**Vegans:** Intelligence comes by degrees. E.g. humans *on average* have 5000 intelligence, cows 500, but dumb, young or crippled people might be near or even below cows.
**curi:** I don't think it's a matter of degree that a human can learn a complex language like English or Japanese and no animal can do anything similar. The same argument goes for doing science or philosophy. Also, there's the issue of what you think intelligence is, which you need to provide a detailed model and explanation of if you want a more rigorous reply.
**Vegans:** Suppose cows and Roombas are both in the non-AGI category which is different than human intelligence in a big way. That doesn't prove cows and Roombas are similar.
**curi:** I agree. That argument puts the ball in your court to *name the trait* that differentiates cows from Roombas (and from AlphaGo and other present day software) in a relevant, important way.
Why are you fake arguing with a sock puppet that thinks like you instead of a real Vegan? This is not what Vegans talk like. Watch Joey Carbstrong doing activism and leaving people "blanking out" with his arguments. Try arguing with him. That would be interesting.
And the issue is not intelligence, it was never intelligence. It's sentience.
The question is: Is there a reason to think there isn't an autonomous consciousness in an animal?
To me the comparison with man made computers is not valid criticism. Creating a simulacra that acts real is not evidence that the real thing is not real or that it's the same as the real thing.
Alan Forrester writes:
> Animals lack the ability to create new explanatory knowledge, unlike people. As a result there is a qualitative difference between animals and humans in that an animal can never make a contribution to the growth of objective knowledge in its own right. Dogs never learn to write, they don't learn English beyond some short list of commands, they can't write music or program computers. The reason is that a dog has a finite bag of tricks written into its genes and when it exhausts that bag of tricks it can't create anything new. Other animals are in the same position. For example, experiments in trying to teach apes language always reach a point where the ape can't do anything more sophisticated than what it already does. See "Kanzi: The Ape at the Brink of the Human Mind" by Sue Savage-Rumbaugh and Roger Lewin for an example. (See also "The Beginning of Infinity", Chapters 15 and 16.)
> The animal has a particular set of knowledge (in the sense of useful or explanatory information) in its genes. So any copy of the relevant genes will have the same knowledge and no individual animal matters very much. By contrast, each person has a unique set of ideas and habits instantiated in his brain and that does matter. Every time a person dies unique ideas are destroyed that might lead to progress. Every time you mistreat a person you make it more difficult to get access to any good ideas he might have or that he might develop.
> You might say that animals can suffer and so this provides another kind of value and that this value is not limited to humans.
> An animal can't understand what is happening to it and so can't interpret the pain as being bad. The idea that something is bad is a sophisticated interpretation of experiences that only arises in the light of a lot of knowledge. For example, one reason people suffer is that they can imagine all the stuff they won't be able to do as a result of injury or death, unlike animals. Animals are robots programmed to propagate genes. To do this, genes program their vehicles to move away from stuff that will damage the vehicle, refrain from using damaged body parts so they can heal, signal danger to relatives and other stuff like that. They bear more resemblance to characters in a computer game than to people.
> You might say that it looks like animals suffer, but that is an interpretation of what you see when you look at an injured animal. The explanation I have given criticises that interpretation. Likewise when you say an animal has a brain structure that is similar to some human brain structure you are imposing a false interpretation of what is going on. Both the human brain and the animal brain are universal computers: they can do anything that a universal Turing machine can do. It follows that you can't tell exactly what it is doing just by looking at the hardware. To the extent that some part of the animal's brain is similar to a person's brain it is participating in a very different process. The computation in the animal's brain doesn't involve understanding what is happening to it or anticipating problems as a result of an injury or anything like that: the animal doesn't suffer.
It seems to be that people don't engage with the jump to universality idea. Why? Don't they understand it?
> Don't they understand it?
I don't think so.
> So any copy of the relevant genes will have the same knowledge and no individual animal matters very much. By contrast, each person has a unique set of ideas and habits instantiated in his brain and that does matter.
In other words, people aren't fungible. Animals in a species pretty much are.
#14881 One of the reasons for this is because animals are born with all their (genetic) knowledge, while humans create (memetic) knowledge during their lives.