[In what follows, I use “vegetarianism” to refer to veganism or vegetarianism.]
[In #3 in the final "Notes" section, I call the meat industry less "labor-intensive" than other industries. I don't mean that the work is less difficult or "intense," but that it employs fewer people. The work is quite taxing, I'm sure.]
Marxism (sort of) and “ethical vegetarianism”
I spent years as a vegan (eating no meat, no dairy, no eggs), motivated by ethical concern for animals. I was particularly militant about this. Like many who share it, I viewed my diet in terms of an informal boycott; I aimed to withhold monetary support from the meat industry, and to that (small) extent impair its ability to torture and kill animals.
I am no longer vegan (nor vegetarian), due in part to the influence of Marxist ideas upon my thinking. At the same time, however, I retain the belief that it is wrong to kill animals for food. (At least, at this stage in human social development, and in the part of the world in which I live.) And I retain this belief for all the reasons I ever held it to begin with.
The difference in my current thinking has to do with the connection between opposing the killing of animals, and being a vegetarian. I don’t think there is much of a connection, in fact. That is, the fact that it is wrong to kill animals does not mean one ought to be a vegetarian. It doesn’t even make vegetarianism a good idea.
Marxism and the moral mushiness of meat
How Marxism relates to this is in its wholesale indictment of production under capitalism. For Marxists and other socialists, how goods are produced—not any particular kind of good, but goods per se—is deeply problematic, always. Without repeating the arguments here, this is due to the kind of relationship direct producers (workers) bear to the owners that pay them to work, and to the fact that production is organized for profit and exchange rather than direct use; these features make the system necessarily undemocratic and exploitative, and contribute to economic crisis and instability, ecological destruction, and even war. These features “cut across” specific sectors and industries within the productive system; they are generic features of capitalist production as such.
In short, such a radical view removes the ability to say: “Believing that a particular industry is fundamentally problematic, one ought to boycott it”—because each industry fits that description, and we can’t boycott them all; we must consume something.
This applies especially to meat since it is not a luxury item which we might simply discard—as we might stop wearing “blood diamonds” or patronizing R-rated movies. For we were getting vital nutrition from that source, and must fill the dietary “hole” left by meat consumption with some other kind of food. And this will come from another deeply problematic industry.
As I discuss below, this does not mean there is no reason, nor even no ethical reason, to not eat meat—only that it removes the moral imperative to do so.
At least, it appears to. Vegetarians might respond that, even if all industries are bad, they aren’t equally bad. Perhaps we are obliged to boycott meat because it is the worst, or a particular reprehensible one.
One argument goes: Killing is worse than (merely) exploiting. So an industry which both exploits human beings and kills animals (i.e., the meat industry) is worse than one which only exploits humans.
But the reality is more complicated. Yes, killing seems worse than exploiting, all things being equal. But things may not be equal. It may not be the case that killing animals is worse than exploiting humans, or, if it sometimes is, that killing just any given number of animals is worse than exploiting just any given number of humans.
Terms for comparison: Not lives, but qualities of life
To clarify the issues at stake, it is helpful to get at what makes killing—any killing—wrong (when it is wrong). What makes killing wrong can only be that “life” has some value which killing destroys. If this is so, we should be able to specify certain features which lend it this value. The obvious candidates are things like autonomy, richness of social relations, capacity for desire satisfaction, etc. These types of thing, or some combination of them, give value to life. And while the list is debatable, it is clear that, by any reasonable measure of what could give value to live, animals will possess some of these features—will have value—just as humans. That is, unless we cheat , we cannot construct a list of things possessed by all and only humans but no animals; if humans have value, then animals do.
It should also be clear that these features admit of varying degrees: One can have more or less richness in social relations, more or less autonomy, than another. If this is so, I contend, the animals killed for meat possess these features to a lesser degree than the adult humans exploited in every industry (including meat). Therefore, they have less value, and it is, though still tragic, less so when they are killed.
Two qualifications are in order:
(1) First, this is not a particularly “anti-animal” view. For it is also the case that some humans (say, infants) have less of these features—thus less value—than some animals (just as some animals have less value than other animals, and some humans less than other humans).
(2) Second, I admit the idea of some people being “worth less” than others is extremely distasteful. It would be unfortunate if the concept entered into everyday conversation. But this is not the same as saying the idea is false, or even particularly sinister. It is merely to say that not every being shares (or can share) the same quality of life. The idea does not, in the extreme case, license any kind of Hitlerian “eugenics”: Saying one can destroy a person because they are less valuable than another is like saying I can destroy your car because it is less valuable than mine. There is no principle of logic nor ethics that necessitates that only the absolutely most valuable entity be suffered to exist. The idea that we can “rank” beings according to value does not mean that it is ever right to kill any of them.
But it does complicate the question of whether one capitalist industry is worse than another. It means we are not are dealing with a simple case of “killing versus exploiting.” In comparing meat to other industries, we are comparing worse treatment of “lower valued” beings (animals) to better treatment of “higher valued” beings (adult humans). If human workers have more value than animals, it could be that they have so much more value that merely harming them is actually worse than killing animals.
This still perversely simplifies the moral question. For one, exploitation among human beings is not equivalent across industries, either. There are degrees of intensity of exploitation: Some workers work harder, longer, and for less pay than others. And there are countless moral categories in play here beside just killing and harming in production: From the same Marxist view, the accumulation of capital (productive wealth) is the drive behind all of the system’s problems; as some industries are more profitable, and reinvest (re. accumulate, rather than spend) more profit, than others, they contribute more to this central dynamic. And this occurs after the production cycle rather than in it. Some non-meat industries may accumulate more, may be more volatile and unstable, may contribute more to global trade and the inequities abroad that follow it. All of this would have to be researched and accounted for in deciding the relative “badnesses” of various industries.
Further, there is no “meat industry” as such to be boycotted—not really. The “borders” between industries are mushy rather than firm. Industries buy from one another; aiding one aids the other. If there were no builders, there would be no henhouses, thus no chicken factory-farms. In this sense, the building industry is the chicken industry—and so forth. Buying anything stimulates a general economy which in turn enriches every industry within it. Opting out of meat in particular means more grains will be bought—enriching the same industry which provides cows and chickens and pigs with (the same) grains. The point is not that “everything is bad so we should not boycott anything”—but rather, it is unclear how we might identify and isolate “anything” to boycott it in the first place.
The poverty of “consumer politics” in general
These issues make it difficult if not impossible to establish that the meat industry is worse than any other. A second question is whether, even if it is worse, not eating meat does anything to affect this situation.
It is clear that if I raise an animal to eat, then change my mind and keep her for a companion, an animal is saved. If I quit hunting, that could save animals. But buying (or ceasing to buy) animals on the market is not analogous to this. In a market economy, we don’t normally “order up” live animals to be killed as we need them. There is no such clear, one-to-one correspondence between individual demand and supply. A gross number of animals are killed (or set aside to be killed) prior to and in anticipation of aggregate demand.
Indeed, as high numbers of “demanders” alter their preferences away from meat, this aggregate sum can, after a time, be altered. But this is a case of very broad trends responding to other broad trends. It is likely that a single person’s opting out of meat consumption saves literally not one animal from slaughter. Certainly, it is unclear how this could be proven if it were true.
Note also that overproduction is the norm here. Even if my going vegetarian lowered demand for meat, it is likely that simply fewer animals would be consumed—not fewer killed. Already-slaughtered animals would simply be “wasted.”
At best, not buying meat withholds, over time, a few dollars’ profit from that industry. This is not the stuff of moral imperatives; for a rather silly analogy, if I dropped a few dollars on the sidewalk, and Hitler picked it up to use in his campaign, I could not rationally be especially bothered. I could sleep securely knowing my “contribution” was symbolic rather than substantial.
Conclusion, Part I: The scope of good ideas is not exhausted by the scope of moral imperatives
Again, all of this argues that a moral imperative to vegetarianism does not (clearly) follow from the immorality of killing animals. It is not as straightforward, for instance, as the way in which the imperative not to poke people in the eye follows from the fact that it is wrong to poke people in the eye. Poking eyes is analogous to killing animals—not to buying meat from animals already killed.
But there are plenty of worthy projects—indeed, the vast uncountable majority of life’s projects—that aren’t imperatives. A thing needn’t be morally obligatory to be a perfectly good or helpful thing to do.
Two appealing “alternate” motivations for vegetarianism come to mind:
(1) Eating meat strikes me as a distasteful, ugly practice, and could be avoided on these “aesthetic” grounds alone. The same kind of reason would keep any parent from tearing a photograph of their children—though no actual children would be harmed in doing so.
(2) Given the wrongness of killing animals, refusing to eat them is a way to feel connected to them, to the whole world of sentient, morally deserving beings of which anyone reading this is a part. We needn’t be obliged to seek this feeling, but it is a healthy, desirable goal. It helps us whether it helps any animals—and we are important, too.
Conclusion, Part II: Consumer politics redux
Finally, what small practical or psychological benefit comes about from “ethical” vegetarianism must be balanced against the harm it could cause. Again, I’m speaking here as a Marxist—a socialist activist—and to others on the radical left for whom vegetarianism is appealing.
The chief political rival to revolutionary socialism is reformism—the idea that socialism, or at least a benign, democratic, peaceful, equitable world, can be generated by a gradual accumulation of small improvements to capitalism. And the most vulgar species of reformism is the notion that the, or a significant, way to bring about political or economic changes is through selective purchasing.
This view is not only false but dangerously misleading. I suspect that vegetarianism—being a particularly common and “visible” expression of consumer politics—confuses the hell out of the average worker or student who might be ripe for radical politics. It “sends a message” that not buying stuff is the way to get things done, the “natural,” proper expression of one’s opposition to social problems.
I can’t prove this, but I suspect it. If true, this confusion can only hinder the real activism that needs to be done—raising enough hell to scare the state into making concessions. If there were strong reasons to boycott meat in the first place, this might outweigh the potential “damage”; but, again, there aren’t.
 Here I am ignoring the possibility that beings have “rights” which make it wrong to kill them. No evidence has ever been adduced that such a thing as natural rights exist, and even if they do, that doesn’t negate my alternative analysis. “Rights” could theoretically exist right alongside those “features” which give life its value. Either or both could make it wrong to kill at the same time. It could be wrong to kill you because it violates your rights and because it destroys your value.
 Speciesists might say that “being human” is what gives value to life—to which we might reply, What is it about being human that gives life its value? What do humans possess that gives human life this value? It is circular reasoning to answer again: “The feature of being human.” Eventually, we have to get back to non-species-specific features.
 Note also that the meat industry is less labor-intensive than many other industries, so there are far more humans exploited in the latter than in the former. This increases the likelihood that meat production is not particularly bad. Consider: If there were an equal number of humans working in the meat industry as in any other industry, this would amount to a moral “wash”; as far as humans are concerned, at least, none would be worse than any other. So any industry which killed animals on top of this would indeed be the worse. But other industries have so many more humans than in meat production that only a small percentage are “washed out” in the comparison. We are not simply dealing with “higher value” beings harmed versus “lower value” beings killed—but rather a significant number of “higher value” beings harmed versus “lower value” killed.