A philosophical question is if it is not morally acceptable to kill another human and eat it, on what grounds can we kill non human animals and eat them? Are we guilty of “speciesism,” the characteristic of which is an unjustified prejudice against other animals? Speciesism can be compared to racism, an unjustified prejudice against other races, or sexism, an unjustified prejudice against a different sex. Peter Singer, a prominent utilitarian philosopher, believes that many people are unjustifiably speciesist. A different prominent philosopher, the late Bernard Williams, an opponent of utilitarianism, believes it not to be so. Both Singer and Williams use aliens to make a related point.
Peter Singer, (Practical Ethics, [Cambridge University Press, Third Edition, 2011], p.68) appears unhappy that we might identify as members of the species Homo-sapiens and would prefer it if we identified as “self-aware beings” or, perhaps, “sentient beings.” He comments. “Personally, I would feel that an intelligent alien with whom I could communicate and share feelings would have more in common with me than a member of my own species who is so profoundly disabled as to be unable to have any conscious experiences at all – even if the latter looked much more like me.”
Bernard Williams, (Philosophy as a Humanistic Discipline, [Princeton University Press, 2006],pp.149-152) implies that if aliens land on earth and wished to live with us, whether they look like us or whether they are slimy and disgusting, “opponents of speciesism [would] want us to join them— join them…on principle.” In his fantasy, such people, presumably Singer included, would be the “collaborators.” Against them would be the “resisters,” those “organizing under the banner ‘Defend humanity’ or ‘Stand up for human beings.’” It is a question of whether people can be loyal to other human beings. The question to ask is “Which side are you on?”
Considering these two positions, I think I would fall into Bernard Williams camp. The nearest real life event to any of these fantasies that comes to mind is when Gary Kasparov, the chess grandmaster, played the IBM supercomputer Deep Blue at chess in the mid to late 1990s. At that point in time I desperately wanted Kasparov to win. The reason for wanting Kasparov to win was because “he’s one of us.” Perhaps I am prejudiced in favour of humans, but I am not convinced that this is unethical.