Using analogies in ethical reasoning.

One of the things we’d like to be able to do with our powers of ethical reasoning is tackle situations where we’re not immediately certain of the right thing to do (or, for that matter, of the reason why the plan someone else is advocating strikes us as wrong).
A common strategy (at least in an ethics class) is to whip out an ethical principle or rule, try to apply it to the situation you’re pondering, and see what it tells you to do: What can I do here that respects the humanity of others and of myself? or, Which of the available courses of action maximizes benefits and minimizes harms (taking into account, of course, that benefits and harms to others matter just as much as benefits and harms to me)? The disadvantages of this strategy is that most of the ethical principles that yield clear judgments in decision scenarios also encounter decisions where they seem to break and give absurd judgments.
An alternative strategy is to take the situation we’re puzzling over and consider how similar or dissimilar it is from one or more cases for which our ethical judgments are clear. This strategy of using paradigm cases to guide our ethical responses to situations that deviate somewhat (but not too much) from the paradigm cases is called casuistry.

This is the kind of strategy I was trying to apply in my earlier post about whether, for the person with a strong ethical objection to the use of animals in biomedical research, it is ethically permissible to make use of medical treatments developed with such research. There, I presented two cases where I felt the ethical judgments were reasonably clear (described in detail in the original post), and I considered which of these two cases was closer to the different case over which I was puzzling.
At least for myself, I found this consideration useful. It helped me put my finger on what bothered me about the “Well, I can use this drug, since the animals used in researching it have already suffered” gambit. (What bothers me is that it doesn’t take account of the fact that using drugs and other medical treatments contributes to the perceived demand for more such treatments. Meeting this demand requires, under current scientific and regulatory conditions, more research with animals. In other words, if stopping animal research is something to which you’re strongly committed, being a consumer of modern medical care tends to work against that commitment.)
As usual, my commenters on that post raised some very good objections.
jrshipley noted that avoiding hypocrisy (say, by maintaining very low standards) is not necessarily a mark of exemplary ethical conduct.
Richard Chappell made the case that apparently conflicting commitments (and actions directed by them) might not even count as hypocrisy:

Suppose you have the following preference ordering:
Medical research (no animal testing) > Medical research (animal testing) > no medical research.
In this case, even though one would prefer (on ethical grounds) that medical research proceed without animal testing, and thus consider it pro tanto bad to incentivize future animal testing through one’s medical purchases, nevertheless one thinks it would be even worse to forego modern medicine altogether.
In that case, there’s nothing remotely hypocritical about using modern medicine. It is not hypocritical to do something that one thinks is pro tanto bad (i.e. bad in some respect). It is only hypocritical to do something that one thinks is all things considered bad.

Here, concern for humans presumably drives the commitment that there should be medical research. Concern for animals drives the preference to avoid using animals in research. If one prioritizes these interests as Richard suggests, some animal research — an the use of medical treatments resulting from it — is ethically permissible. Given that our ethical commitments do, in various circumstances, pull us in different directions, prioritizing them is something we have to do to avoid being stuck in our tracks fearful of hypocrisy. That a strong commitment gets sacrificed in some cases (in favor of an even stronger one) does not prevent us from clinging tightly to it and acting upon it in conditions that allow us to do so.
Many of the other comments pointed out various ways in which the case over which I was puzzling departed significantly about which my intuitions were clear:

• Gov. Bureaucrat: When in the supermarket, it is an easy matter to walk past the meat case and on to the vegetable section. With what you find there, it will be possible to craft an acceptable alternative to eating meat. One need not sacrifice health or well-being to forgo the meat (and, indeed, it may even be healthier to do so.) …
  The situation in medical research is not analogous. Computer models and cell/tissue culture can answer certain questions that would have, in the past, required animal research. However, no one (outside the animal rights community) would argue that they are “perfectly viable” alternatives to animal research.
• Sandra Porter: The problem with this analogy is that a person who fails to utilize some of the modern medical tools, like vaccination, makes a choice that could imperil others.
  This happened last year when there was a mumps outbreak in Vancouver.
  No one imperils others when they bypass the meat section in the grocery store.
• neurowoman: I think a better analogy than the meat market, from the point of view of the animal rightists, is the problem of whether or not to use the results of Nazi expts on humans: do you shun these results as if these didn’t exist even though they could save lives, or use the results while stipulating that no such experiments are ever ethical?

This is a risk inherent with analogical reasoning. No analogy is perfect (else it would be an identity, not an analogy). The question really comes down to whether the analogy is good enough to illuminate the features crucial in deciding whether a particular plan of action would be ethical or unethical. (Here, recall that we were evaluating whether a particular plan of action would undermine someone’s stated opposition to, and commitment not to contribute to additional, animal suffering.)
Casuistry doesn’t demand perfect analogies. Rather, it prompts us to act, which of these cases does the situation under consideration most resemble? If it seems halfway between the two cases that serve as our benchmarks, that probably means we need to come up with another nearby case where our intuitions are clear — on we hope will be a better analogy for the puzzling case than either of the two benchmark cases already on the table.
So, what should we say about the departures from a perfect analogy raised above?
While I appreciate the observation that the supermarket generally offers viable eating options that are not meat-laden, I’m not entirely sure that the claim that there is no viable alternative to modern medical care captures the justifications given by people arguing against animal research while helping themselves to the fruits of such research. Generally, their argument is along the lines of, “What’s done is done, but now, no more!” This is quite a different justification from, “There are, at present, no good options that didn’t rely on animal testing, although there could be, if only scientists would listen to us and stop using animals in their research!” (If these people objecting to animal research on ethical grounds are also arguing against it on the basis that results of research with animals cannot be reliably applied to understanding and maintaining human health, then conceding the success of modern medicine built with animal research is a somewhat mind-bending maneuver.)
The fact that, in actuality, many people do go without modern medical treatments, whether because they opt for “alternative” modalities instead, or because they fall through the cracks of the health care system cannot afford such treatments, is another wrinkle that complicates the (dis)analogy between medical care and supermarket meat counter. My own sense is that this state of affairs tends to undermine the claim that animal research objectors have to use modern medical treatment in a way supermarket shoppers do not have to use meat.
On the matter of whether the analogy breaks down because opting out of medical treatments (like vaccines) can cause harm to others, again, I recognize the weight of this argument (and am swayed by it in vaccinating my own family), but I don’t think this kind of consideration is often voiced in the actual justifications offered by those who would end all animal research for their use of medical treatments. This particular flaw with the analogy, in other words, doesn’t seem to bear on whether the justification offered for this behavior holds up. (It may be possible that the behavior itself would pass muster if bolstered by better reasons — perhaps like the ones Richard suggested, above.)
Then there’s suggestion that a better analogy for opposing animal research while utilizing medical treatments developed with such research than either of my two benchmark cases would be using knowledge obtained through Nazi medical experiments. In many ways, from the point of view of the person opposing animal research, this is the closest analogy. However, if we’re using casuistry to try to get clear on the ethics of this, I don’t think this particular analogy helps us.
For one thing, while the Nazi regime (and the medical experiments conducted under its auspices) ended, current biomedical research involving animals has not. Thus, utilization of knowledge in one case provides evidence of demand for such research (spurring continued funding, from public and private sources, for more such research), while in the other case it does not because the Nazi medical research programs are no more.
For another thing, I suspect that people don’t have especially clear intuitions about whether it’s ethical to use the knowledge obtained from Nazi medical experiments to inform current medical treatments (e.g., of hypothermia). I know I don’t have clear ethical intuitions here. Without clear intuitions, the Nazi case is not a good benchmark to help us evaluate the case we’re using casuistry to try to figure out.
But with the aid of some reasonably close benchmark cases for which our ethical judgments are clear, maybe casuistry could help us get clearer on the ethics of using knowledge from Nazi medical experiments, too.