I would say that the test of consciousness is an ability to think conceptually and abstractly. Self awareness usually includes the ability to be embarassed. I think it was Mark Twain who said "Man is the only animal that can blush, or needs to". You can argue all day long about whether animals are capable of this, as I see you have done. But the important thing is, is there proof for, or against this argument? When humans became conscious, for whatever reason, they moved out of caves and developed a society, for only in a society can one have social contracts. What proof is there that animals are capable of this type of thought? Have they invented any kind of techology? Beavers build dams, just as birds build nests, but stacking debris together I think is instinctual, not cognitive. Language is a technology, humans developed language, a system of abstract symbols for things. No animal species has developed a language to my knowlege, because in my opinion the test for language is that it be possible for others to learn it. ie-a dog born to an owner, and raised by that person all its life, never learns to speak with his owner, why is this? Humans can learn he language of other humans, why can't animals learn the language of humans, or other animals? I saw something about Hellen Keller earlier, even being blind and deaf, she was able to learn the language, or at least how to communicate. Why has no animal ever done this? So as Murray Rothbard put it "we will give animals rights when they petition for them". As far as children and the mentally handicaped go, I would assert that they are the property of the people who care for them, likely the parents. And don't come back at me with the argument that, 'well what if the parent molests the child, or someone takes advantage of the handicaped' because that is to confuse law with moraity. Hopefully even the lowliest of fools knows better than to try to legislate morality. Even though an animal might be property I would never kick my dog for sport. Anyway, if you really are interested in this question, you have a lot of reading to do. Try some philosophy, start with Descartes. Cogito ergo sum - I think therefor I Add or something to that effect, my latin is a little rusty