Whenever people agree with me I always feel I must be wrong. (Hans-Peter Geerdes)

If you know me, you will know that animal rights are a very important topic to me. I am a vegetarian, and already tried to become a vegan, which I couldnt manage so far, unfortunately. Till some years ago I had a pet - a dog which I loved and I was very sad when he died. This dog was one of the most important sources of my belief in the value of animal life.

I always loved animals somehow. I grew up in a village with a lot of farms, e.g. cowsheds and piggeries, which were there before the time when reasonable animal protection laws were introduced in germany, thus the cows were chained and the pigs were pent-up. But since I grew up there and already saw some pigs being slaughtered, this was a normal thing to me. I loved cows and pigs, but I never thought about them suffering in the position they were. Well, until the farm of our neighbours burned down, with about a dozen cows and bulls (iirc), and some pigs. This was the first time when I considered becoming vegetarian - when you see cows dying in a fire, you really think about whether you can still eat them. But well, I was about 9 years old, and at some point, I started to eat meat again, I stopped it again about 6 years later if I remember correctly.

Meanwhile, a lot has changed, and animal protection, as well as animal rights, have become a topic of wide interest, at least in germany. And at least in germany, almost no catering can afford not to offer at least some vegetarian food. There are a lot of motivations for vegetarianism, actually, just not wanting an animal to die for oneself is meanwhile considered naive, compared to the many other reasons like health and environment. Anyway, environment protection always comes along with animal protection, but has always been a medium, not a major goal to me.

At school, some teachers almost went crazy because I wouldnt let them tell me that there is a moralic difference between humans and animals. But I simply couldnt see one. I didnt consider the main arguments that were given to me being thought through.

For example, the main argument for this is probably (still) the superior intelligence and consciousness of humans. A funny fact about this is that our school was next to a home for the handicapped, and therefore we were often told that we have to respect mentally disabled people, as they are also humans and also have a right to live. I am not only talking about people with down-syndrome or similar diseases, which may be less intelligent than average people, but can take part at normal life when aided properly. I am talking about really disabled people, people which live their entire (mostly short) lives bound to a wheelchair, sometimes being blind, sometimes being deaf, sometimes being unable to move, mostly being heavily distorted. There are people which have an intelligence inferior to some animals - and I want them to have human rights, too. But if I evaluate living things by their intelligence, it wouldnt be consistent anymore. Unfortunately, most people simply stopped the discussion at this point, comparing my argumentation to social darwinism, but in fact it is not me who is evaluating life forms by terms of evolution - they do, by extolling themselves over animals.
Furthermore, while the human intelligence may mostly be superior to other animals, there are other facilities in which other kinds are superior. Eagles have superior sight, monkeys are superior at climbing, cats are superior at jumping, birds and bats can fly. These facilities have evolved by evolution, and it turns out that intelligence is somehow superior to them, because in the end, it gives you the power of controlling other kinds, and copy their facilities by technology. So yes, intelligence a great thing, but I dont see the relevance for moral decisions.

Another argument which is often given is that animals have much higher reproduction rates than humans. Since they have, it is no problem to torture and kill a few of them, since there are still enough of them left. Thus, not considering an animal as an individual, but as part of a large group of animals, which are only thare to reproduce and keep up their kind.
Some animals like mice may have a very high reproduction rate, but others like elephants and rhinos, do not. Hence, this is not true for all kinds of animals. And one has to think about the high reproduction rates of humans in ancient times - there are more than 6 billion people out there, vitally no place on earth is not inhabited by humans. That is a lot, more than some other species. And I doubt that the reproduction rate of humans would be so low if we didnt have contraceptives. If we rate the value of an individual animal by its meaning for the population of its species, why should we do something else with humans, therefore devaluating infertile, gay or even unalluring people. We would have to give humans an additional value to justify this argument to give humans an additional value - this is circular reasoning.

Yet another argument I often hear is that if other animals were superior to us, they would do the same to us. From the arguments given so far, this one is the one that is still the most plausible to me, as it doesnt try to extoll humans to animals, but see them as a species like any other, which just has the luck of being mightier than the others. So from all of the given arguments, this is the only one that I appreciate for trying to really analyze the situation.
But well, this is an assumption. There is no proof for this. There are animals which are herbivores and would therefore certainly not eat other kinds of animals, but on the other hand, its plausible that they would still have some use of other animals, like producing manure for growing plants, or doing heavy work. On the other hand, there are a lot of humans who do not want to suppress animals. Hence, it is plausible that members of other species would also, at some point, consider this morally wrong. Maybe their process of making political decisions differs from ours, and hence it could happen that this awareness of the suffering of other kinds would spread faster than under humans. The main problem here is, that we cannot say much about intelligent species, since we basically know only one, and we cant be sure to be impartial when evaluating it, since we belong to it.
And in my opinion, if we can learn one related thing from ourselves, then it is that power without responsibility almost always leads to problems. We have the power to do almost everything we want, so we should also take responsibility.

There may be still a lot of space left for debates, but lets move on. Lets say, we accept animal rights so far. Lets think about the reason why we want this kind of "rights" anyway.

I think, most people will agree that the concept of basic "rights" is there to minimize, or at least to border suffering. We all know how certain kinds of suffering feel, and we assume that other humans feel the same, and thus, there are human rights. Higher animals behave anthropomorphic when feeling pain, so they are also given some rights, because we assume that these animals feel similar to us. Fish, while having an anatomically different way of feeling pain, also behaves in a way that we see if it feels pain. It behaves like we would intuitively expect by something that feels pain.
Lower animals like insects or spiders do not behave this way. But still, if you pull out their wings or legs, they intuitively seem to suffer from it, they do not behave like they dont care. Earthworms and snails also seem to behave as we would expect from something that feels pain. So somehow, we may not have a problem with poisoning snails that are destroying our garden, but most people have a problem with stepping on a snail or worm and seeing it being convulsed with pain.
Some people even give plants basic rights, like frutarians that only eat what can be harvested without killing the plant. As this is a rather modern movement, there is not much thinking done yet. There are some plants that want to be eaten, or at least do take an advantage of it, like tomatoes. There are some plants that regularly die every year, like corn, which is usually harvested when it is already parched. There are also plants which can reproduce themselves by dropping branches which then take roots themselves, like the chinese willow.
On the other hand, there are plants that react on being hurt by sending out poison and messengers to other plants, like acaciae. Intuitively, this is some sort of pain, and we maybe should try to take care of it.

Now, after giving a slight introduction to that topic, lets move on to the reason for this post anyway, and the topic I want to get at.

I can remember a lot of interesting discussions in my biology course at school. One was about the chances and risks of genetic engineering. Animals could suffer from genetic manipulation, which is a risk. On the other hand, I made the suggestion of maybe someday being able to create animals without a brain and therefore could not feel pain. My teacher answered that this would also be a torture to that animal. At this point I didnt quite understand what she meant. And recently, two people asked me what I think about animals without a CNS.
While in the cases mentioned before it is rather clear what "suffering" and "pain" means, in these cases it is not. We can even go further and talk about machines that behave like feeling pain, and there are films about this topic. With the Holo Doctor in Star Trek: Voyager this kind of problem occurs many times, same for Data. The film A.I. is almost entirely about that topic. Though this is currently just science fiction, there may come a day when we will be able to create an artificial life form in that way, and then we will run into these problems.

In the end, this boils down to two questions: What is "pain" and "suffering", and what is "live" at all. This leads to an even more general problem, and there is an interesting essay by Paul Graham about it. While giving a lot of other interesting statements, one statement is that "the concepts we use in everyday life are fuzzy, and break down if pushed too hard". And thats somehow the case here. We dont have an universal definition of "pain", there is no formal system that can really decide that for us. Maybe someday we will have such a system, but for now, we just have to make the best out of what we have by now, and you will always find edge cases in which this definition is not clear or even makes no sense. The foundations of mathematics were not built up in one day, and there are many theories that were less formal, before somebody finally invented a strictly formal system around them. We need to take this problem serious and think about it, so we can maybe find a consistent formal system one day that also satisifes our intuition. But until we have it, we must not throw away theories just because of edge cases in which they may not be consistent. However, you may have noticed that I also used some edge cases in my argumentations - that is because I claim that my thoughts handle these edge cases better, but it doesnt mean that there may not be a superior theory that can handle with the edge cases of my thoughts. Every theory I know has some flaws, and it is a common and easy way of trolling people to show them these flaws, because most people are simply never thinking that far, but its not a proper way of reasoning, when the own theory is inferior.

What remains is the question what to do then. How can we behave morally correct.

I think the first thing we can learn of all this is that we simply have to accept that the world is a cruel place. We cannot live without giving death, pain and suffering to other living things. But we also cannot die, because inside us there is a strong will to survive, which can not be broken by the "everyday-suffering", and which makes us taking high efforts for saving it.
In the end, I think, one just has to accept that as a given fact, and make the best out of it. We must accept that we want to live, even though this means that other creatures must be killed, but we should at least be aware of it. We need to think about how much suffering we have to produce, and minimize it as far as possible. And we need to always respect the things that may suffer from us. The real problem is not humans harvesting corn, but humans who dont take it serious that this corn may suffer in some way, and laugh about people thinnking about this.

Not long ago, I was told a proposition which is probably the best thing to do: Try to behave better than the average person.
It is impossible to be perfect - especially because we cannot even tell what "perfect" means at all. It can be very exhausting to try to be perfect, especially when you cannot conform to your own requirements, and at that point, it may even be counterproductive, because other people might see you fail and that might keep them from trying to behave better themselves. If you do as much as you can, then maybe you will inspire other people to do the same. If one person behaves perfectly (whatever that means), but nobody else does, it doesnt help anybody. But if many people try to be better that the average person, the world could get better.