Bump to explain my own thoughts but to say that I started this thread because I'd like to expand my perspective and better form an opinion:
At the moment this is my stance on animal rights:
Certain animals which science has some reasonable reason to believe are conscious, a list which includes cuttlefish, octopuses, dolphins and whales, elephants, most primates, and so on, should be given the benefit of the doubt - i.e., assume they are conscious and afford to them something similar to human rights. My reason for believing this is similar to my reason for wanting a better justice system - there would be nothing worse than thinking someone is guilty/not-conscious and then punishing/exploiting them as such, only to find out later that you were wrong, they were innocent/conscious.
Therefore I am an animal rights advocate in the case of these animals.
Briefly describing what I mean by consciousness here: self-awareness or the ability to have internal discursive thought. Though this is at present very difficult to determine, some indicators can make us more or less sure it is there like complex language, larger brains, complex problem solving skills and so on. Science may hopefully shed more light in the coming years.
What I am *not* talking about is emotions. I am aware that most, even many mammals or even animals (or plants) in general have emotions, many almost exactly analogous to human emotions (we got them from somewhere, right?) such as fear, anger, depression, and happiness.
The existence or proof of these emotions in animals does not affect my view on the morality of the treatment of these animals *IN THE ABSTRACT*.
To explain further: A dog, for instance, may feel fear or pain. But, if the dog is not conscious, there is no entity, no one there, upstairs if you will, to appreciate that pain and fear are being felt. So yes, the brain is processing it and reacting to it, but there is no one inside the dog to whom it is happening. An animal without a consciousness, even an emotional one, remains an automaton. So, essentially, I would not say one is obligated to feel moral anguish for a dog who was hunted by a bear and died in fear and pain.
However, I want to elaborate this a bit, because you are probably jumping to the wrong conclusions about me. This does not mean I think dog fighting is okay. Why? Because we as humans *are* conscious and *do* interact with animals and, rationally or not, personify with them and interact with them emotionally. And since we *are* conscious, it does matter, to us, what happens to them emotionally, since we can sympathize and empathize.
Thus, if you murder my dog, you've done a bad thing, because I loved the dog. Not because of the dog himself who may have been afraid, but because of me, who loved the dog and will feel pain empathizing with his fear.
Also because killing living things is unbecoming of human beings with consciousnesses.
Thus, inhumane slaughterhouses *are* morally reprehensible in an intrinsic sense, because of the effect they have on a society that knowingly endorses them and on the people that interact with them regularly, and because of the effect that has on people's view on the nature and value of life.
Thus, our human tendency to relate more with animals that are closer to us in appearance or evolution, at its base morally irrational, becomes morally rational since this process involves human emotion and behavior, the primary concerns of morality.
So, since nobody *really* cares if I crush an ant or a flea or a fly or exterminate a bacteria colony, then it's morally not an issue. But since there *are* people who care if I torture cats, and since this will probably even affect me, the torturer, negatively, then it matters, and its morally wrong.
So there you go.
On vegetarianism, a slight aside. There is another, in my opinion much more important reason much carnivorousness is immoral, besides inhumane treatment of empathizable animals, and it relates to the environment and social justice. Eating meat is often an inefficient use of agricultural resources and/or a strain on the environment. This harms everyone, especially but not limited to those who have food supply problems. You can eat a pound of beef that took 10 pounds of grain, but only *after* the rest of the world has enough grain, to put it in simplistic terms. That's a different kettle of fish (herp derp) though, so yeah.