Would medical research on animals ever be justified from a perspective like Singer's or Regan's?

Animal welfare (utilitarianism): Yes, if the harms prevented to humans outweigh the harms caused to animals.

Animal rights (Regan's rights view): Yes, if the worse-off principle applies. (Click here for the illustration of this principle's use, noting that this would seem to be a case where the worse-off principle applies, because non-comparable harms are involved, and it would seem to imply the choice of option #2, even if the aggregate harm would be larger.)

Singer: Researchers exaggerate the likelihood and/or magnitude of benefits to humans.

Note how similar Singer's ethical perspective is to researchers', at least when it comes to animals who lack a robust sense of their future, about whom Singer therefore thinks in hedonistic utilitarian terms. Insofar as researchers tend to:

• justify research in utilitarian terms, and

• think of animal well-being in purely hedonistic terms,

their basic ethical perspective is precisely the same as Singer's!

The disagreement between Singer and the research establishment, then, is less a matter of ethical principle than it is an empirical dispute about how likely various lines of research are to have benefits and how significant those benefits are likely to be.

Regan: You might expect Regan to think that some research, at least medical research realistically calculated to save human lives, would be morally permissible, because the worse-off principle applies (that is, when human lives are saved, a non-comparable harm is prevented).

However, Regan denies that harmful research on animals is permissible even to save human lives. His reasoning is that a "special consideration" blocks the application of the worse-off principle.

In The Case for Animal Rights, Regan argues that where certain "special considerations" apply, it is not appropriate to evaluate actions and institutions in terms of the mini-ride and worse-off principles. One of these "special considerations" concerns involuntary transfers of risk. Regan claims that "Risks are not morally transferable to those who do not voluntarily choose to take them" (p. 377), and points out that this is precisely what happens in almost all medical experimentation.