Let the last thread "on" the topic be consigned to history.

Here is the proposition:

(1) We, as human animals, should kill non-human animals for our purposes, whatever they may be.

You can affirm it or deny it. Syllogize, philosophize, justify, provide evidence. Poetry may help you, but poetry is usually suspect for analogical reasoning that can be questioned and equivocation. But it may give a useful model. Metaphor can sometimes move the greatest of minds where argument falls flat.

Obviously vegetarianism consists in the denial of (1). Most who affirm (1) do so on basis of some Cartesian or quasi-Cartesian thesis:

(2) Non-human animals (like dogs) are this, but humans are that.

It follows, under the Cartesian assumptions/axioms, that (1) be justified by (2). "This" and "that" sometimes stand for "automata" and "rational agents," respectively. But the form of the argument is what is Cartesian. Its content is too. But what's important for our purposes is that for the "Cartesian Argument," one assumes a dichotomy and certain consequences follow. You can replace "this" and "that" with whatever you wish, so long as the two hold some kind of dichotomous relation.

1. Humans are rational.
2. Dogs are not.
3. Therefore, humans can torture, eat, etc dogs.

Cartesian dualism seems to impose or presuppose some methodology or logic, aside from being a substantive metaphysical thesis. But moving on...

Some preliminaries

A proper discussion of the topic should, at least, have a clear beginning so that we might be able to reasonably judge when we've gone off the main road. I cite this not invoke negative feelings, but vegetarianism is a rather broad topic. It's difficult to know where to begin, and it seems almost pointless to imagine a conclusive end condition to any argument involving it.

What I will do is start us off from what is simple, then we may venture, should we have the right impetus, to what is complex. By "simple" I merely mean that I shall wish to give you basic arguments or questions. By "simple" I do not mean that this OP will be brief. I simply wish to give us an appetizer to snack on, then we move on to the full course in due time. You might wish to pick at this OP here or there, and we can coherently and accurately entertain your question or counter through the quote system, like a breadcrumb trail.

To round us up: we'll be centering on whether we ought to kill animals for consumption. We will not be entertaining the question of the "most ethical way to round up animals and consume them." This is by its very nature a political question, which presupposes a choice about the former. Ethically killing animals is still killing animals; and we're out to determine whether it is ethical to kill animals. Presumably, the pro-vegetarian would like to see that animals are killed with as much regularity as humans on, on roughly the same conditions (alike in kind of committing grave moral sins against other humans, acting on (immoral) maxims, murdering, committing adultery, etc). Yes, it sounds very odd to think of a non-human animal committing adultery. Just how far are we willing to grant animals "equality"? What exactly does equality mean? If you shudder at the thought of non-human animal marriage, then perhaps you would like to guide me to exactly those contours of the concept of "human as equal to non-human animal." I do not joke; I take your claim, should you hold it, to its (valid) logical extreme.

Back to the point: We're concerned with whether it is or is not moral to kill animals as animals. We might ask: "Might it be immoral to kill an non-human animal because it would be like killing a human?" What about all living things?

The Original Poster

My own position will be in favor of dogmatic skepticism about vegetarianism. Thus, I hold that you cannot (in the sense that it is not possible) be justified in your vegetarian, and thus moral, belief that animals should not or should be killed for consumption.

Essences and the Is-Ought dichotomy

The first and possibly only determining factor is whether animals have the same moral status as humans. The question then becomes What constitutes the moral status of humans?

We cannot look to physiological differences. Whether or not we wish to accept the consequence of ruling out infants, the senile and mentally challenged as having the same moral status as "normal" humans is irrelevant. We'd still have the is-ought gap which would not allow us to derive that, say, "We ought not kill animals" from "Animals are just like infants." We'd just be left with the question of why we ought not kill infants.

The interesting question is whether we could take all those justifications for why we ought not kill infants and displace those justifications onto animals.

So, for instance, we ought not kill infants because that would bring about the demise of humanity. But surely this ought claim is nothing more than a slippery slope. What is it, intrinsically, if there be anything intrinsic, about infants that makes it immoral to kill them? Or must we always appeal to an external justification? Does it make sense to talk about the essences of things?

Further, would the determined "essence" of a thing fit squarely into the "is" of the is-ought dichotomy? Is a metaphysical-is any different from a natural/physical-is? I answer in the affirmative. Whether we deduce affirmatively the "rationality" and "consciousness" of non-human animals to be of the same kind as humans, this would not thereby validate our ought-claim. It would only show that we have consequences to bear if we accept that ought claim. But our claim was never justified. It was merely a decision or a whim or a preference (though perhaps a preference that involved in-depth argument; e.g., picture how you might argue that one film is "objectively" better than other, or that the film adaption is "objectively always" worse than the original novel; does the mere conclusion of the argument make your preference any less of a preference? Is an "objective preference" somehow no longer a preference?)

Preference Vegetarianism

This last question is very much related to my own personal view that I held for a time. I was a Pyrrhonian skeptic about justified moral belief, which withholds assent from skepticism and its denial. My affirmative thesis was that all views on vegetarianism were justified only as preferences (which do not count as a kind of justification at all). But if there was any justification to speak of, preference would be it. I held that no person was justified in holding another to be immoral or moral in his or her views about the ought-claim in question (Where it is or is not moral to kill (and eat) animals.). My negative thesis just was my positive one.

Of course, this is different from merely killing and eating animals. It makes no sense to speak of "justifiedly killing an animal." We might say of a person who does kill an animal that he or she is acting immorally or morally and that his or her act follows from a maxim which is not justified. This was my view. Your maxim, should you act upon one, is not justified. Your maxim, as argued, could not be justified. If justified as a preference, then as a preference there is little to say.

The Social, The Economic

But in a strange sense, you can speak of having a subjective, preferential view that is justified in some sense. Perhaps an appeal to majority. Simply imagine a possible world where "the rule of the majority" is a valid justificatory move. Honestly, the majority "validates" many of our actions in this actual world. Think of tenure, presidential races, whether or not it is a "good idea" to go to a party as you wonder amongst your friends, etc. And if it doesn't validate it in some sense, it certainly is at least a determining factor.

Picture how much of vegetarianism is largely justified in terms of social consequences or "politics." For a while, I was sold on the argument that was somewhat of a slippery slope. "If you treat animals in such a way for so long, under such harsh conditions, you'll eventually ruin your resource. Thus, we'll have no non-human animals to nourish and supply us." This is a terrible formulation of it, but you get the idea. Is this a plausible justification? Of course, we can ask: Should we accept it? It's social-normative, but not moral, it seems.

One major determining factor in my no longer being vegetarian is my economic demographic and my location. Some city locales simply don't make vegetarianism a viable economic alternative. How might this fact be related to the proposition? You could see as asserting: Morality must be grounded in the world. Can we entertain moral justifications as if these social, economic, political factors are just hypotheses? Can we postulate a "possible world" in which the political and economic spectrum therein contorts and bends to our moral bias? How convincing is argument of this nature?

But one might say "that's no basis for a moral decision!" And I might even be condemned more for having such an egoistic outlook nevertheless. But we might respond: What else am I to do? Thus, it becomes a question of knowledge. What if I don't have the pragmatic-epistemic, the know-how, capacity to arrange and adjust my life in such a way to follow such a guiding principle as the denial of (1). We could do a very interesting dance with this topic.

Categories and Regress

To outline categorical maneuvers:

Again: (1) We, as human animals, should kill non-human animals for our purposes, whatever they may be.

You can either argue:

(i) From normative premises but no moral premises.

[INDENT](The moral is a kind of the normative; e.g., a whale is a kind of mammal. If something is moral, it follows that it is normative. If something is normative, it does not follow that it is moral. So, politico-normative, scientific normative, social norms, etc)
[/INDENT]

(ii) From no normative premises.

[INDENT](So perhaps factual premises, but beware the naturalistic fallacy and the is-ought gap. Any argument that (flagrantly) employs this category, on most accounts, will be viewed as suspect of fallacy. This is a fact.)[/INDENT]

(iii) From moral premises.

[INDENT](Of course, this move is subject to the skeptical regress argument. Any moral premise, if the conclusion is denied, which is (1), will be equally or subject to similar denial; and so on. Basically, we can always question a vegetarian moral premise. It may take some work, which is likely the point of this thread.)[/INDENT]