Why We May Use Animals
Before returning to the arguments for animal rights, I would like to present a classical-individualist case for the use of animals for human purposes. Without this case reasonably well established, it will not be possible to critically assess the case for animal rights. After all, this is a comparative matter -- which viewpoint makes better sense and therefore is more likely to be true? Moreover, it was from a roughly classical-individualist stance that the idea of basic rights was developed, by John Locke and others.
One reason for the propriety of our use of animals is that we are more important or valuable than other animals and some of our projects may require the use, even killing, of animals so as to succeed. Notice that this is different from saying that human beings are “uniquely important,” a position avidly ridiculed by Stephen R. L. Clark, who claims that “there seems no decent ground in reason or revelation to suppose that man is uniquely important or significant.” If man were uniquely important, that would mean that one could not assign any value to plants or nonhuman animals apart from their relationship to human beings. The position I am defending is that there is a scale of importance in nature and among all the various kinds of being, with human beings prima facie the most important -- even while some members of the human species may indeed prove themselves to be the most vile and worthless as well.
How do we establish that we are the most important or valuable? By considering whether the idea of lesser or greater importance or value in the nature of things makes clear sense and applying it to an understanding of whether human beings or other animals are more important. If it turns out that ranking things in nature as more or less important makes sense, and if humans qualify as more important than other animals, there is at least the beginning of a reason why we may make use of other animals for our purposes -- for instance, when a trade-off is unavoidable.
That there are things of different degree of value in nature is admitted by animal rights advocates, so there is no need to argue about that here. When they insist that we treat animals differently from the way we treat, say, rocks -- so that we may use rocks in ways that we may not use animals -- animal rights or liberation champions testify, at least by implication, that animals are more important than rocks. They happen, also, to deny that human beings rank higher than other animals, or at least they do not admit that ranking human beings higher warrants our using animals for our purposes. But that is a distinct issue. What matters for now is that variable importance in nature is at least implicitly admitted by defenders of the high moral status of animals.
Quite independently of this acknowledgment, there simply is evidence through the natural world of the existence of beings of greater complexity and of higher value. For example, while it makes no sense to evaluate as good or bad such things as planets or rocks or pebbles -- except as they may relate to human purposes -- when it comes to plants and animals, the process of evaluation commences very naturally indeed. We can speak of better or worse oaks, redwoods, zebras, foxes, or chimps. While at this point we confine our evaluation to the condition or behavior of such beings without any intimation of their responsibility for being better or worse, when we start discussing human beings, our evaluation takes on a moral component. Indeed, none are more ready to testify to this than animal rights advocates, who, after all, do not demand any change of behavior on the part of nonhuman animals and yet insist that human beings conform to certain moral edicts as a matter of their own choice. This means that even animal rights advocates admit outright that to the best of our knowledge, it is with human beings that the idea of moral responsibility enters the universe.
Clearly, this shows a hierarchical structure in nature: Some things – rocks, comets, minerals -- do not invite evaluations at all -- it is of no significance, except in relationship to the well being of some living entities, whether they exist or what condition they are in or how they behave. Some things – zebras, frogs, redwood rees -- invite evaluation as to whether they do well or badly but without any moral or ethical implications. And some things -- namely, human beings -- invite moral evaluation in light of the fact that they exercise choice regarding good and bad things they can do.
The level of importance or value may be noted to move from the inanimate to the animate world, culminating, as far as we now know, with human life. Normal human life involves moral tasks, and that is why we are more important than other beings in nature -- we are subject to moral appraisal; it is a matter of our doing whether we succeed or fail in our lives.
Now, when it comes to our moral task, namely, to succeed as human beings, we are dependent upon reaching sensible conclusions about what we should do. We can fail to do this and too often do so. But we can also succeed. The process that leads to our success involves learning, among other things, what it is that nature avails us with to achieve our highly varied tasks in life. Clearly, among these highly varied tasks could be some that make judicious use of animals -- for example, to find out whether some medicine is safe for human use, we might wish to employ animals. To do this is the rational thing for us to do, so as to make the best use of nature for our success in living our lives. That does not mean that we can do without guidelines for how we might make use of animals -- any more than we can do without guidelines for how we use anything else. In a discussion of ethics, such guidelines would become essential but they are not the topic of politics or law in a free society (except when animals or plants become the subject of contractual agreements and their enforcement).
The above line of reasoning also counters a frequently raised objection to our use of other animals: Could not the same argument be used within the human species, giving better people the right to make use of worse people? The answer is that making choices is a precondition for determining who is better or worse among human beings, and using people against their will squelches their choice -- at least with respect to what they ought to do next -- so those who are better have the obligation to leave those who are worse to continue to make choices that may well reverse the situation. It isn’t over, as the saying goes, until the fat lady sings, so, as we have learned from Aristotle, the comparative assessment of human beings must await the completion of their lives, at least in principle.
Of course, we do in fact “make use” of some very bad people -- those who have been duly convicted of having exempted themselves from human community life. We banish -- usually by imprisonment -- those who violate others’ basic rights. We punish them at times by forcing them to work -- for example, to produce license plates in the United States. Personally, too, there are limits to tolerance: if someone threatens us with serious harm, with taking our lives or property, we act to remove the threat, to subdue the aggressor. This is not outright “using” of someone, but it does show that for self-defensive purposes, human beings are not immune from being killed or maimed, akin to how we might treat animals if they stand in the way of our flourishing.

I think your argument is far too anthropocentric to even take as a serious comment on the issue of hierarchy. The enormity of the universe and of metaphysics and anything else we do not understand is such that your scale that places humans at the pinnacle is like saying the earth is flat without having taken that ship to check it out.
Please refrain from making your self sound as though you have something remotely accurate to say until you've thought through all the possibilities.
Of what value is there to being a moral agent if we use it to turn furry animals into coats, reptiles into wallets, cows into happy meals, and elephants into dancing behemouths. Where is this superiority and wisdom that you speak of that places us on mount zeus?
Evaluation or ranking of any kind implies that there is an agent who is doing the evaluating! Can such evaluation be impartial? In this case the agent is us- which makes the evaluation kind of biased?! How can such evaluation possibly be 'natural' or 'neutral'? Also the word 'important' requires us to establish-important for whom and for what? Again, the answer is 'important' to us. We are more important to us. After all we are not more important to animals than animals are to themselves? Indeed, this is almost a theistic argument implying that there is a universal criterion for the ranking of 'importance' or value and furthermore, we have been let in on the secret scale used, while animals have not, hence they have no idea they are not important! But we know better.
When it comes down to it, the argument is that difference equals superiority or inferiority, measuring everything on a hierarchical scale. Nevermind the fundamental cores of human and nonhuman animals are the same, nevermind this is an excuse to treat living beings as property. This same argument is used by racists, sexists.....speciest are no different.
The fundamental cores of humans and animals naturally fall into hierarchies. Unless you don't believe in all that food chain crap those speciest put out there to fool the rest of the world.
Species ARE different. That's why we call them different species. Humans are not different species despite having different colour skin, eyes, noses, etcetera. Women are not different species from men (though it certainly does seem like it at times). There is a difference between a pig and human. Different species, different abilities, different functions.... different. Pigs have their place in nature and guess what? If we don't kill wild pigs we're going to soon have a huge problem on our hands when it comes to agriculture.... you know... agriculture? That thing that is so great that we should stop eating animals for, because apparently humans were never designed to eat meat at all? Despite the fact that before inventions such as plastic (which wreak havoc on the environment in all aspects), killing animals for clothing and other useful tools was not only common place, but also necessary. But ohhhh let's just drill and mine and destroy the planet for more oil to make more stuff to fuel more things for stuff we don't need so we dont' feel guilty about using animals as another resource to fuel our bodies and keep us warm (amongst other things). Sounds like a great plan.
It matters not their "importance." It matters not your perception of their "value."
What matters are simply these two things:
1) Do they suffer?
2) Can we prevent that suffering?
Then why do you allow the suffering of children in Africa?
Why don't you use all your disposable income to save women and children who have no food and water in the Congo? You could prevent that suffering with the money you spend on your hair, on clothing, on vegan goodies? If you own a pet, that pet costs you money for the vet, and to have spade/neutered .So you make a value judgement by being vegan/ vegetarian which arguably causes a child suffering elsewhere in the world, as you could save a child for $35 a month and you choose not to. As you put it, is it about do they suffer and can we prevent that of suffering. In your case you are just as guilty, but you prefer one type of animal over another.
Abstaining from eating dead body parts doesn't cost me any money . I also contribute money to unicef. So I can do both easily, save NHAs by not eating them and contribute to children in Africa financially.
If that is your argument then when are you becoming vegan because like me you can do both. Unless that really isn't your argument in which case I await your real argument.
Would you save an animal life over a human life? (For instance, there's a run away train. If you do nothing, the train will kill the human child who is wandering on the tracks... forget about why there's a human child on the tracks... there just is. However, you can throw the switch and the train will move onto another track. There is a calf on the other track. What do you do?)