All the polemics and analyzes of vegetarian diets I’ve ever seen have proceeded as follows: begin from facts about meat eating diets that implicate the eater in a causal chain which includes violence of some sort that the eater ought not implicate him or herself in. This is not a new or strange way of doing moral reasoning – it may in fact be the only way. However, it does have some implications which are not normally considered explicitly.
For example, if we begin from a principle as simple as “it is wrong to kill a sentient being”, and a second one, “it is wrong to involve oneself in causal chains, other links of which are morally unacceptable”, then we get, “it is wrong to eat meat because it implicates the eater in a causal chain, another part of which involves the killing of sentient being which is morally wrong”.
This is all fine and good, but you immediately have the “I live in society” problem, because you can link your existence in society in the way that it is to many causal chains which have morally reprehensible elements, such as colonization, wars for oil, systematic racism and sexism. Many horrors of the past were necessary for us today to have the kind of existence that we have, and we might even want to say it is only because the labour standards in other countries are so low that we can afford to set our labour standards so high and still afford basic goods (because those goods are produced by labour which is more exploited than labour here).
So, it becomes untenable to simply revoke menbership in every causal chain which has unspeakable violence somewhere in it. Still, we can say it is right to be vegetarian because we must at least remove ourselves from those causal chains where we have the freewill to do so (we do not have the free choice not to be born into a society based on inequality and violence). However, there is always the problem of suicide – killing oneself would remove oneself from all causal chains of violence. But, we do not want to say that suicide is the highest moral act – we know it is an act of cowardice.
We might say that when we say “it is wrong to involve oneself in a causal chain the other end of which is violence”, this statement is just shorthand for the more basic ethical principle of, rather than minimizing the wrong, of maximizing the good – and we might think the wrong radically cancels out good so it is better to eliminate a small bit of wrong rather than create a lot of good. This would seem to get around the problem of untenable ethical principles. However, there are a few implications of resorting to the Utilitarian framework.
First, it is unclear what the good is. Utilitarianism is not so much a moral theory as a theory of economic calculation where the monetary unit is the good. Certainly we do not want to say that pleasure is the good, so we need something more complex. It turns out that Utilitarianism solves the moral problem only if we have already solved the problem of what the good is (perhaps “the good” is like “being” – a notion we always use all the time without being able to bring our implicit understanding of it to explication).
Second, no rules are hard and fast. Rules become rules of thumb – needing to be reevaluated at crucial points of decision to see if that rule which appears to apply actually does apply, actually does maximize the good. The position of reifying oneself with rules of thumb is just another way of forgetting the real moral dilemma and turning oneself into a machine – the opposite of man. The reified position is one which acknoledges that its actions are wrong in certain situations and does them anyway, “just because those are the rules”.
So, taking for granted that a utilitarians rules for vegetarianism cannot be hard and fast, what does this mean for his actions? It means that while it is fine to as a rule of thumb not to eat meat, in the same way as it is fine as a rule of thumb not to kill people, s/he must acknowledge that s/he may come across cases where the rule breaks down, where the rules gives the wrong answer. And if challenged on one of these occaisions, one cannot appeal to the rule but only to the reasons behind the rule.
So, the utilitarian ends up being a kind of deliberator – with rules of thumb but those rules must be evaluated for propriety in terms of a concrete situation. E.g. if two rules come into conflict (i.e. you can save a child from an axe murderer but only by sharing a steak dinner with the killer), it is no good appealing to the rules themselves, or the priority of certain rules over others. If this was the case, then we could say the rules were primitive and we would not be utilitarians at all but deontologists through and through. In actuality, we must evaluate the situation in light of the reasons behind the rules, and through this determine which rule, if either, is the appropriate one to follow in concrete situation.