The issue with expanding animal rights has to do with the issue of expanding Human Rights. You can't tell an animal to forget how to use its innate impulses. An animal won't stop being an animal. Only in small ways are most animals of a subjective existence. There's not enough subjective world to their world that they have to reconnect their instincts by using subjectivity. You can make some animals forget the point of their impulses but you can't give them the agnosia we suffer from by telling them "the way things are" and filling their heads with lies.

Subjectivity is inexorably separate from reality. Subjectivity can never perfectly reflect objectivity. Telling someone "how it is" will always miss something or at least tell them something wrong. You can write the biggest most complex lexicon on even the simplest of things and you'll still forget something even if you didn't make an outright mistake. That's why enculturation is a subjective disease I call "subjective-agnosia." There's possibly a few exceptions.

Examples, "every rule has an exception" (and its exception) "everything is a poison; it's simply a matter of dosage" which is a furtherance of "truth exists independently of you and your belief of it."

This said, if you have human rights AND animal rights, you have to treat animal rights lower than human rights or you run into the problem of giving animals more rights than yourself and have to amend human rights to fit animal rights. You can tell a lioness not to harass a lion until he's ready to rape her but she'd probably kill you. It's what lions are made to do and so are you. It's proven by the fact that makes good sense to you.... It either makes good sense or you'd be eaten by a lioness.... If not a lion....

Religion, drugs, and eunuchs, are the source of inhumanity. for better and/or much worse. What could possibly be more morbid than being subject to a eunuch?

Psychosis is the only thing that separates us from animals.

Rationality is just a poorly defined value term for an undermined number of times our inner contrarians threw the ball back and forth before our inner umpire called foul.

Subjectivity itself is psychosis. It's not until you know where you are that you can know where you're going. Scribbles don't mean anything without the collectivist psychosis that they do.

In English, something you drink from is a "Cup." In Spanish, something you drink from is a "Taza." So which is it? Is it a Cup or a Taza. Is it both? Doesn't it exist independently of whatever you'd like to call it? It may as well be an Aschenbecher.

Truth exists independently of you and your beliefs. You exist in a socialy constructed collectivist psychosis. You're a living anthropomorphic argumentum ad populum fallacy.

We may be making too much of this 'rights' thing. Descartes was just as limited as anyone else when he started ranting about an 'immaterial soul'. Whether humans (or any other advanced animal life, mammal or no) have an immaterial soul is very much a matter of belief, inasmuch as we have not figured out a way to demonstrate the existence of immaterial souls. We, as civilized humans, grant rights to one another, individually and on broader social bases. This separates us from the vulgar savage and the 'unfeeling beast'. So, this idea of rights had to begin some-when, probably around the time of the codification of language(s). It had little (or nothing?) to do with non-humans---sub-humans, maybe, but this begins to split hairs. It was part of advancement of civilizations and getting along with people outside of one's own sphere of everyday life.
On this topic I have opined before, claiming that we are getting wrapped up in animal rights because it makes us feel better and presents itself a a worthy cause, but, DOES it offer any sort of well-grounded rewards? I mean, for example, animals to whom we are offering rights have no notion of anything being different, do they? No, there is no reason nor advantage to acting towards them with malice and cruelty. Our best friends (dogs, I mean) act with love and loyalty towards their owners and human families, committing acts of bravery and saving human lives. If someone treats them badly, they probably do not consciously understand why that is happening. Nor do they understand why someone would intentionally starve them. My point, if it may be considered one, is that those of us who value animal life which is below our own will continue to do so. Those who don't won't. Whether or not this is a rights issue, then, depends upon who is looking at the matter. And, insofar as we have found out, the hard way, that we cannot legislate morality among ourselves, how does it follow that we can do so between ourselves and our canine; feline; anthropoid friends? This is another fight, while perhaps worth fighting, seems unlikely to be winnable. Seems to me.
(As to mixing religion and other forms of philosophy, it greatly muddies the water, yielding a product which is neither.)

Bacteria show some aversion to threats. Does that give them non human rights. Would I be insane to say yes to that? I think not if a group of the bacteria acted as one being on a scale that could be compared to human consciousness.

Consciousness is the boundary condition for extending rights to non humans. Some simple tests are currently being done called Zap and Zip which compliment an Integrated Information Theory (IIT) approach to consciousness assessment. The philosophical underpinning of this theory is panpsychism if I'm reading this literature correctly. Though Zap and Zip is a simple test and independent of IIT - this sort of quantitative approach shows promise. I agree that the mirror test, pain and feeling are too vague and open to allow extending legal rights.

It's important for philosophers to understand the stakes of the current scientific debates regarding emotion and feeling. Damasio's allusion to emotion as a higher order mental circuit are just the begining of a very active and pitched battle with very real stakes and deep consequence.

Finally, I would say, this has real significance in the effort to bring about the singularity. IIT research is key to this effort. There is a very deep distinction between consciousness and intelligence. Artificial Intelligence is seen as the harbinger of the coming singularity. It is not. Artificial consciousness is.

Ok, I lied. Here's my final offer. I'm stuffed. It's Thanksgiving and I ate ... I'm full. Everything I ate... was vegan. The Jainists are right. Let's fix this planet and industrial cruelty in one swoop. That is a non human right that will fix many wrongs. Happy Thanksgiving.

Bravo, Tim, Bravo. I have an acquaintance who is very much into the notion of time travel. Claims to being close to solving it...I don't know how close he thinks he is. On the other hand, he is suspicious of the pitfalls of AI---thinks nothing good can come of it. Seems an enigma in some sort of way, yet, there you are.

I think, in the last rational (?) analysis I can think of, the notion of extending rights to animals might turn on what we think about primary consciousness (that found in some higher animals) vs. higher-level consciousness (that shown by humans). These are terms of art posed by the late Gerald Edelman in some of his writings. By way of illustrating my point, I will excerpt here a portion of one of my recent efforts concerning the 'mystery' of consciousness:

...Explaining Consciousness

It is a tall order, I think. The so-called explanations I have read are, well, book length. Although they have been conceived and prepared by scholarly minds and have (mostly) withstood the trials-by-fire of peer review, the fact of the matter is this. Quite a lot is known ABOUT consciousness, whereas efforts to explain it have fallen short of the goal. It is obvious, for example, that human consciousness gives rise to capacities, abilities and capabilities unseen in other life forms: they are able to cope well enough with their realities but have not the imagination or ingenuity to use abstraction. The human advantage entails not only dealing with the things which ARE but also visualizing those that might BE. Consciousness is the totality of circumstances emanating from the human mind. That is my short explanation, which is, of course, also inadequate...

I have no quarrel with being kind to animals. There are no reasons why we should not. But we ought not impart to them the same sort of bill of rights which we afford ourselves, just because they have no ability to argue their own case. There are better uses to be made of our system of laws, and our limited view of morality.

If we imagine our brain as a black box, an input will enter and the correspondent output will exit. In animals, that process might be more straigh-forward, yet they are able to respond to stimuli just as we do.
I think that what makes us human different is that we can question that same process of thoughts.
What is happening inside our black box right now? Is it really something WE are thinking, or just an input-output mechanism? Are these then concious thoughts?
We are trying to analyze our thinking process by using that same element as a tool. It’s like the uroboros, a loop. Even now, when I am thinking about how I think, I have no real way of knowing if the questioning of my thinking process was just part of it or I somehow managed to escape that loop.
I believe we humans can escape that loop: by reflecting (which the initial trigger was is still something I don’t know) we start rearranging our thinking circuits and develop, as we shape our vision of reality, unavoidable subjective, and keep asking questions.